diff --git a/Source/Core/AudioCommon/Mixer.h b/Source/Core/AudioCommon/Mixer.h
index 2a1a62ba4f..b47f7b204c 100644
--- a/Source/Core/AudioCommon/Mixer.h
+++ b/Source/Core/AudioCommon/Mixer.h
@@ -99,7 +99,7 @@ private:
   bool m_is_stretching = false;
   AudioCommon::AudioStretcher m_stretcher;
   AudioCommon::SurroundDecoder m_surround_decoder;
-  std::array<short, MAX_SAMPLES * 2> m_scratch_buffer;
+  std::array<short, MAX_SAMPLES * 2> m_scratch_buffer{};
 
   WaveFileWriter m_wave_writer_dtk;
   WaveFileWriter m_wave_writer_dsp;
diff --git a/Source/Core/AudioCommon/OpenALStream.h b/Source/Core/AudioCommon/OpenALStream.h
index c252838568..812f0a9019 100644
--- a/Source/Core/AudioCommon/OpenALStream.h
+++ b/Source/Core/AudioCommon/OpenALStream.h
@@ -53,7 +53,7 @@ class OpenALStream final : public SoundStream
 {
 #ifdef _WIN32
 public:
-  OpenALStream() : m_source(0) {}
+  OpenALStream() = default;
   ~OpenALStream() override;
   bool Init() override;
   void SetVolume(int volume) override;
@@ -68,9 +68,9 @@ private:
   Common::Flag m_run_thread;
 
   std::vector<short> m_realtime_buffer;
-  std::array<ALuint, OAL_BUFFERS> m_buffers;
-  ALuint m_source;
-  ALfloat m_volume;
+  std::array<ALuint, OAL_BUFFERS> m_buffers{};
+  ALuint m_source = 0;
+  ALfloat m_volume = 1;
 
 #endif  // _WIN32
 };
diff --git a/Source/Core/Common/Config/ConfigInfo.h b/Source/Core/Common/Config/ConfigInfo.h
index 824947cfb6..e59239b881 100644
--- a/Source/Core/Common/Config/ConfigInfo.h
+++ b/Source/Core/Common/Config/ConfigInfo.h
@@ -23,7 +23,7 @@ using UnderlyingType = typename std::enable_if_t<std::is_enum<T>{}, std::underly
 
 struct Location
 {
-  System system;
+  System system{};
   std::string section;
   std::string key;
 
diff --git a/Source/Core/Common/FileUtil.h b/Source/Core/Common/FileUtil.h
index e2021bdab4..9c1116943c 100644
--- a/Source/Core/Common/FileUtil.h
+++ b/Source/Core/Common/FileUtil.h
@@ -85,11 +85,11 @@ enum
 
 namespace File
 {
-// FileSystem tree node/
+// FileSystem tree node
 struct FSTEntry
 {
-  bool isDirectory;
-  u64 size;                  // File length, or for directories, recursive count of children
+  bool isDirectory = false;
+  u64 size = 0;              // File length, or for directories, recursive count of children
   std::string physicalName;  // Name on disk
   std::string virtualName;   // Name in FST names table
   std::vector<FSTEntry> children;
diff --git a/Source/Core/Common/FixedSizeQueue.h b/Source/Core/Common/FixedSizeQueue.h
index a303cce4cd..dc58aab865 100644
--- a/Source/Core/Common/FixedSizeQueue.h
+++ b/Source/Core/Common/FixedSizeQueue.h
@@ -78,7 +78,7 @@ public:
   bool empty() const noexcept { return size() == 0; }
 
 private:
-  std::array<T, N> storage;
+  std::array<T, N> storage{};
   int head = 0;
   int tail = 0;
   // Sacrifice 4 bytes for a simpler implementation. may optimize away in the future.
diff --git a/Source/Core/Common/IOFile.h b/Source/Core/Common/IOFile.h
index 858e634933..873c4c2af5 100644
--- a/Source/Core/Common/IOFile.h
+++ b/Source/Core/Common/IOFile.h
@@ -59,9 +59,9 @@ public:
   }
 
   template <typename T, std::size_t N>
-  bool ReadArray(std::array<T, N>& elements, size_t* num_read = nullptr)
+  bool ReadArray(std::array<T, N>* elements, size_t* num_read = nullptr)
   {
-    return ReadArray(elements.data(), elements.size(), num_read);
+    return ReadArray(elements->data(), elements->size(), num_read);
   }
 
   template <typename T, std::size_t N>
diff --git a/Source/Core/Common/LinearDiskCache.h b/Source/Core/Common/LinearDiskCache.h
index e6a1b29557..5f9f7589d4 100644
--- a/Source/Core/Common/LinearDiskCache.h
+++ b/Source/Core/Common/LinearDiskCache.h
@@ -153,7 +153,7 @@ private:
                   std::min(Common::scm_rev_git_str.size(), sizeof(ver)));
     }
 
-    u32 id;
+    u32 id = 0;
     const u16 key_t_size = sizeof(K);
     const u16 value_t_size = sizeof(V);
     char ver[40] = {};
@@ -161,5 +161,5 @@ private:
   } m_header;
 
   File::IOFile m_file;
-  u32 m_num_entries;
+  u32 m_num_entries = 0;
 };
diff --git a/Source/Core/Common/Logging/ConsoleListener.h b/Source/Core/Common/Logging/ConsoleListener.h
index cd1984af6d..7310204377 100644
--- a/Source/Core/Common/Logging/ConsoleListener.h
+++ b/Source/Core/Common/Logging/ConsoleListener.h
@@ -14,5 +14,5 @@ public:
   void Log(Common::Log::LOG_LEVELS level, const char* text) override;
 
 private:
-  bool m_use_color;
+  bool m_use_color = false;
 };
diff --git a/Source/Core/Common/SPSCQueue.h b/Source/Core/Common/SPSCQueue.h
index 96f5b90eeb..27a0a8f282 100644
--- a/Source/Core/Common/SPSCQueue.h
+++ b/Source/Core/Common/SPSCQueue.h
@@ -98,7 +98,7 @@ private:
         delete next_ptr;
     }
 
-    T current;
+    T current{};
     std::atomic<ElementPtr*> next;
   };
 
diff --git a/Source/Core/Core/ActionReplay.h b/Source/Core/Core/ActionReplay.h
index 96c4127d10..13b6294d30 100644
--- a/Source/Core/Core/ActionReplay.h
+++ b/Source/Core/Core/ActionReplay.h
@@ -16,10 +16,10 @@ namespace ActionReplay
 {
 struct AREntry
 {
-  AREntry() {}
+  AREntry() = default;
   AREntry(u32 _addr, u32 _value) : cmd_addr(_addr), value(_value) {}
-  u32 cmd_addr;
-  u32 value;
+  u32 cmd_addr = 0;
+  u32 value = 0;
 };
 constexpr bool operator==(const AREntry& left, const AREntry& right)
 {
diff --git a/Source/Core/Core/BootManager.cpp b/Source/Core/Core/BootManager.cpp
index cac7f1574d..a9a0014155 100644
--- a/Source/Core/Core/BootManager.cpp
+++ b/Source/Core/Core/BootManager.cpp
@@ -64,44 +64,44 @@ public:
 
   // These store if the relevant setting should be reset back later (true) or if it should be left
   // alone on restore (false)
-  bool bSetEmulationSpeed;
-  bool bSetVolume;
-  std::array<bool, MAX_BBMOTES> bSetWiimoteSource;
-  std::array<bool, SerialInterface::MAX_SI_CHANNELS> bSetPads;
-  std::array<bool, ExpansionInterface::MAX_EXI_CHANNELS> bSetEXIDevice;
+  bool bSetEmulationSpeed = false;
+  bool bSetVolume = false;
+  std::array<bool, MAX_BBMOTES> bSetWiimoteSource{};
+  std::array<bool, SerialInterface::MAX_SI_CHANNELS> bSetPads{};
+  std::array<bool, ExpansionInterface::MAX_EXI_CHANNELS> bSetEXIDevice{};
 
 private:
-  bool valid;
-  bool bCPUThread;
-  bool bJITFollowBranch;
-  bool bSyncGPUOnSkipIdleHack;
-  bool bFloatExceptions;
-  bool bDivideByZeroExceptions;
-  bool bFPRF;
-  bool bAccurateNaNs;
-  bool bMMU;
-  bool bLowDCBZHack;
-  bool bDisableICache;
-  bool m_EnableJIT;
-  bool bSyncGPU;
-  int iSyncGpuMaxDistance;
-  int iSyncGpuMinDistance;
-  float fSyncGpuOverclock;
-  bool bFastDiscSpeed;
-  bool bDSPHLE;
-  bool bHLE_BS2;
-  int iSelectedLanguage;
-  PowerPC::CPUCore cpu_core;
-  int Volume;
-  float m_EmulationSpeed;
-  float m_OCFactor;
-  bool m_OCEnable;
-  bool m_bt_passthrough_enabled;
+  bool valid = false;
+  bool bCPUThread = false;
+  bool bJITFollowBranch = false;
+  bool bSyncGPUOnSkipIdleHack = false;
+  bool bFloatExceptions = false;
+  bool bDivideByZeroExceptions = false;
+  bool bFPRF = false;
+  bool bAccurateNaNs = false;
+  bool bMMU = false;
+  bool bLowDCBZHack = false;
+  bool bDisableICache = false;
+  bool m_EnableJIT = false;
+  bool bSyncGPU = false;
+  int iSyncGpuMaxDistance = 0;
+  int iSyncGpuMinDistance = 0;
+  float fSyncGpuOverclock = 0;
+  bool bFastDiscSpeed = false;
+  bool bDSPHLE = false;
+  bool bHLE_BS2 = false;
+  int iSelectedLanguage = 0;
+  PowerPC::CPUCore cpu_core = PowerPC::CPUCore::Interpreter;
+  int Volume = 0;
+  float m_EmulationSpeed = 0;
+  float m_OCFactor = 0;
+  bool m_OCEnable = false;
+  bool m_bt_passthrough_enabled = false;
   std::string sBackend;
   std::string m_strGPUDeterminismMode;
-  std::array<WiimoteSource, MAX_BBMOTES> iWiimoteSource;
-  std::array<SerialInterface::SIDevices, SerialInterface::MAX_SI_CHANNELS> Pads;
-  std::array<ExpansionInterface::TEXIDevices, ExpansionInterface::MAX_EXI_CHANNELS> m_EXIDevice;
+  std::array<WiimoteSource, MAX_BBMOTES> iWiimoteSource{};
+  std::array<SerialInterface::SIDevices, SerialInterface::MAX_SI_CHANNELS> Pads{};
+  std::array<ExpansionInterface::TEXIDevices, ExpansionInterface::MAX_EXI_CHANNELS> m_EXIDevice{};
 };
 
 void ConfigCache::SaveConfig(const SConfig& config)
diff --git a/Source/Core/Core/DSP/DSPCore.h b/Source/Core/Core/DSP/DSPCore.h
index 6455349a09..c61ac3940e 100644
--- a/Source/Core/Core/DSP/DSPCore.h
+++ b/Source/Core/Core/DSP/DSPCore.h
@@ -279,10 +279,10 @@ struct DSP_Regs
 struct DSPInitOptions
 {
   // DSP IROM blob, which is where the DSP boots from. Embedded into the DSP.
-  std::array<u16, DSP_IROM_SIZE> irom_contents;
+  std::array<u16, DSP_IROM_SIZE> irom_contents{};
 
   // DSP DROM blob, which contains resampling coefficients.
-  std::array<u16, DSP_COEF_SIZE> coef_contents;
+  std::array<u16, DSP_COEF_SIZE> coef_contents{};
 
   // Core used to emulate the DSP.
   // Default: JIT64.
diff --git a/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.cpp b/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.cpp
index 1d3b2768de..756529e89a 100644
--- a/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.cpp
+++ b/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.cpp
@@ -100,8 +100,7 @@ static Gen::OpArg GetRegisterPointer(size_t reg)
 #define STATIC_REG_ACCS
 //#undef STATIC_REG_ACCS
 
-DSPJitRegCache::DSPJitRegCache(DSPEmitter& emitter)
-    : m_emitter(emitter), m_is_temporary(false), m_is_merged(false)
+DSPJitRegCache::DSPJitRegCache(DSPEmitter& emitter) : m_emitter(emitter), m_is_temporary(false)
 {
   for (X64CachedReg& xreg : m_xregs)
   {
@@ -188,13 +187,10 @@ DSPJitRegCache::DSPJitRegCache(DSPEmitter& emitter)
     m_regs[i + DSP_REG_AXL0].shift = 0;
     m_regs[i + DSP_REG_AXH0].shift = 16;
   }
-
-  m_use_ctr = 0;
 }
 
 DSPJitRegCache::DSPJitRegCache(const DSPJitRegCache& cache)
-    : m_regs(cache.m_regs), m_xregs(cache.m_xregs), m_emitter(cache.m_emitter),
-      m_is_temporary(true), m_is_merged(false)
+    : m_regs(cache.m_regs), m_xregs(cache.m_xregs), m_emitter(cache.m_emitter), m_is_temporary(true)
 {
 }
 
diff --git a/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.h b/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.h
index 5a05415a38..24bc45b2e6 100644
--- a/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.h
+++ b/Source/Core/Core/DSP/Jit/x64/DSPJitRegCache.h
@@ -170,14 +170,14 @@ private:
   void MovToMemory(size_t reg);
   void FlushMemBackedRegs();
 
-  std::array<DynamicReg, 37> m_regs;
-  std::array<X64CachedReg, 16> m_xregs;
+  std::array<DynamicReg, 37> m_regs{};
+  std::array<X64CachedReg, 16> m_xregs{};
 
   DSPEmitter& m_emitter;
   bool m_is_temporary;
-  bool m_is_merged;
+  bool m_is_merged = false;
 
-  int m_use_ctr;
+  int m_use_ctr = 0;
 };
 
 }  // namespace DSP::JIT::x64
diff --git a/Source/Core/Core/Debugger/Debugger_SymbolMap.h b/Source/Core/Core/Debugger/Debugger_SymbolMap.h
index a8c3cd854d..38bac8f7fa 100644
--- a/Source/Core/Core/Debugger/Debugger_SymbolMap.h
+++ b/Source/Core/Core/Debugger/Debugger_SymbolMap.h
@@ -15,7 +15,7 @@ namespace Dolphin_Debugger
 struct CallstackEntry
 {
   std::string Name;
-  u32 vAddress;
+  u32 vAddress = 0;
 };
 
 bool GetCallstack(std::vector<CallstackEntry>& output);
diff --git a/Source/Core/Core/Debugger/Dump.cpp b/Source/Core/Core/Debugger/Dump.cpp
index 327056a85b..96d8f5b8cf 100644
--- a/Source/Core/Core/Debugger/Dump.cpp
+++ b/Source/Core/Core/Debugger/Dump.cpp
@@ -9,7 +9,7 @@
 #include "Common/CommonTypes.h"
 #include "Common/IOFile.h"
 
-CDump::CDump(const std::string& filename) : m_pData(nullptr)
+CDump::CDump(const std::string& filename)
 {
   File::IOFile pStream(filename, "rb");
   if (pStream)
diff --git a/Source/Core/Core/Debugger/Dump.h b/Source/Core/Core/Debugger/Dump.h
index 647e3f5e5b..32a1795bb9 100644
--- a/Source/Core/Core/Debugger/Dump.h
+++ b/Source/Core/Core/Debugger/Dump.h
@@ -27,9 +27,9 @@ private:
     STRUCTUR_SIZE = 0x2BC
   };
 
-  u8* m_pData;
+  u8* m_pData = nullptr;
 
-  size_t m_size;
+  size_t m_size = 0;
 
   u32 Read32(u32 _pos);
 };
diff --git a/Source/Core/Core/Debugger/RSO.h b/Source/Core/Core/Debugger/RSO.h
index 67ab431533..dc5d61e8ab 100644
--- a/Source/Core/Core/Debugger/RSO.h
+++ b/Source/Core/Core/Debugger/RSO.h
@@ -131,7 +131,7 @@ public:
   u32 GetImportsNameTable() const;
 
 private:
-  RSOHeader m_header;
+  RSOHeader m_header{};
   std::string m_name;
   u32 m_address = 0;
 };
diff --git a/Source/Core/Core/FifoPlayer/FifoAnalyzer.h b/Source/Core/Core/FifoPlayer/FifoAnalyzer.h
index ff9f9460d7..4e167cbc9f 100644
--- a/Source/Core/Core/FifoPlayer/FifoAnalyzer.h
+++ b/Source/Core/Core/FifoPlayer/FifoAnalyzer.h
@@ -22,8 +22,8 @@ struct CPMemory
 {
   TVtxDesc vtxDesc;
   std::array<VAT, CP_NUM_VAT_REG> vtxAttr;
-  std::array<u32, CP_NUM_ARRAYS> arrayBases;
-  std::array<u32, CP_NUM_ARRAYS> arrayStrides;
+  std::array<u32, CP_NUM_ARRAYS> arrayBases{};
+  std::array<u32, CP_NUM_ARRAYS> arrayStrides{};
 };
 
 void LoadCPReg(u32 subCmd, u32 value, CPMemory& cpMem);
diff --git a/Source/Core/Core/FifoPlayer/FifoDataFile.cpp b/Source/Core/Core/FifoPlayer/FifoDataFile.cpp
index 76e151fcd3..16f4c2ba64 100644
--- a/Source/Core/Core/FifoPlayer/FifoDataFile.cpp
+++ b/Source/Core/Core/FifoPlayer/FifoDataFile.cpp
@@ -120,19 +120,19 @@ bool FifoDataFile::Save(const std::string& filename)
   PadFile(m_Frames.size() * sizeof(FileFrameInfo), file);
 
   u64 bpMemOffset = file.Tell();
-  file.WriteArray(m_BPMem, BP_MEM_SIZE);
+  file.WriteArray(m_BPMem);
 
   u64 cpMemOffset = file.Tell();
-  file.WriteArray(m_CPMem, CP_MEM_SIZE);
+  file.WriteArray(m_CPMem);
 
   u64 xfMemOffset = file.Tell();
-  file.WriteArray(m_XFMem, XF_MEM_SIZE);
+  file.WriteArray(m_XFMem);
 
   u64 xfRegsOffset = file.Tell();
-  file.WriteArray(m_XFRegs, XF_REGS_SIZE);
+  file.WriteArray(m_XFRegs);
 
   u64 texMemOffset = file.Tell();
-  file.WriteArray(m_TexMem, TEX_MEM_SIZE);
+  file.WriteArray(m_TexMem);
 
   // Write header
   FileHeader header;
@@ -285,27 +285,27 @@ std::unique_ptr<FifoDataFile> FifoDataFile::Load(const std::string& filename, bo
 
   u32 size = std::min<u32>(BP_MEM_SIZE, header.bpMemSize);
   file.Seek(header.bpMemOffset, SEEK_SET);
-  file.ReadArray(dataFile->m_BPMem, size);
+  file.ReadArray(&dataFile->m_BPMem);
 
   size = std::min<u32>(CP_MEM_SIZE, header.cpMemSize);
   file.Seek(header.cpMemOffset, SEEK_SET);
-  file.ReadArray(dataFile->m_CPMem, size);
+  file.ReadArray(&dataFile->m_CPMem);
 
   size = std::min<u32>(XF_MEM_SIZE, header.xfMemSize);
   file.Seek(header.xfMemOffset, SEEK_SET);
-  file.ReadArray(dataFile->m_XFMem, size);
+  file.ReadArray(&dataFile->m_XFMem);
 
   size = std::min<u32>(XF_REGS_SIZE, header.xfRegsSize);
   file.Seek(header.xfRegsOffset, SEEK_SET);
-  file.ReadArray(dataFile->m_XFRegs, size);
+  file.ReadArray(&dataFile->m_XFRegs);
 
   // Texture memory saving was added in version 4.
-  std::memset(dataFile->m_TexMem, 0, TEX_MEM_SIZE);
+  dataFile->m_TexMem.fill(0);
   if (dataFile->m_Version >= 4)
   {
     size = std::min<u32>(TEX_MEM_SIZE, header.texMemSize);
     file.Seek(header.texMemOffset, SEEK_SET);
-    file.ReadArray(dataFile->m_TexMem, size);
+    file.ReadArray(&dataFile->m_TexMem);
   }
 
   if (!file.IsGood())
diff --git a/Source/Core/Core/FifoPlayer/FifoDataFile.h b/Source/Core/Core/FifoPlayer/FifoDataFile.h
index 63c474bbc7..236f82e8b9 100644
--- a/Source/Core/Core/FifoPlayer/FifoDataFile.h
+++ b/Source/Core/Core/FifoPlayer/FifoDataFile.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <array>
 #include <memory>
 #include <string>
 #include <vector>
@@ -25,18 +26,18 @@ struct MemoryUpdate
     TMEM = 0x08,
   };
 
-  u32 fifoPosition;
-  u32 address;
+  u32 fifoPosition = 0;
+  u32 address = 0;
   std::vector<u8> data;
-  Type type;
+  Type type{};
 };
 
 struct FifoFrameInfo
 {
   std::vector<u8> fifoData;
 
-  u32 fifoStart;
-  u32 fifoEnd;
+  u32 fifoStart = 0;
+  u32 fifoEnd = 0;
 
   // Must be sorted by fifoPosition
   std::vector<MemoryUpdate> memoryUpdates;
@@ -63,11 +64,11 @@ public:
   bool HasBrokenEFBCopies() const;
   bool ShouldGenerateFakeVIUpdates() const;
 
-  u32* GetBPMem() { return m_BPMem; }
-  u32* GetCPMem() { return m_CPMem; }
-  u32* GetXFMem() { return m_XFMem; }
-  u32* GetXFRegs() { return m_XFRegs; }
-  u8* GetTexMem() { return m_TexMem; }
+  u32* GetBPMem() { return m_BPMem.data(); }
+  u32* GetCPMem() { return m_CPMem.data(); }
+  u32* GetXFMem() { return m_XFMem.data(); }
+  u32* GetXFRegs() { return m_XFRegs.data(); }
+  u8* GetTexMem() { return m_TexMem.data(); }
   u32 GetRamSizeReal() { return m_ram_size_real; }
   u32 GetExRamSizeReal() { return m_exram_size_real; }
 
@@ -93,13 +94,13 @@ private:
   static void ReadMemoryUpdates(u64 fileOffset, u32 numUpdates,
                                 std::vector<MemoryUpdate>& memUpdates, File::IOFile& file);
 
-  u32 m_BPMem[BP_MEM_SIZE];
-  u32 m_CPMem[CP_MEM_SIZE];
-  u32 m_XFMem[XF_MEM_SIZE];
-  u32 m_XFRegs[XF_REGS_SIZE];
-  u8 m_TexMem[TEX_MEM_SIZE];
-  u32 m_ram_size_real;
-  u32 m_exram_size_real;
+  std::array<u32, BP_MEM_SIZE> m_BPMem{};
+  std::array<u32, CP_MEM_SIZE> m_CPMem{};
+  std::array<u32, XF_MEM_SIZE> m_XFMem{};
+  std::array<u32, XF_REGS_SIZE> m_XFRegs{};
+  std::array<u8, TEX_MEM_SIZE> m_TexMem{};
+  u32 m_ram_size_real = 0;
+  u32 m_exram_size_real = 0;
 
   u32 m_Flags = 0;
   u32 m_Version = 0;
diff --git a/Source/Core/Core/HW/AddressSpace.cpp b/Source/Core/Core/HW/AddressSpace.cpp
index 8bb2c4cee8..c140132efd 100644
--- a/Source/Core/Core/HW/AddressSpace.cpp
+++ b/Source/Core/Core/HW/AddressSpace.cpp
@@ -354,8 +354,8 @@ struct SmallBlockAccessors : Accessors
   }
 
 private:
-  u8** alloc_base;
-  u32 size;
+  u8** alloc_base = nullptr;
+  u32 size = 0;
 };
 
 struct NullAccessors : Accessors
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AX.h b/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
index d0f73a6c2e..a9ddab8e08 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
@@ -82,24 +82,24 @@ protected:
   };
 
   // 32 * 5 because 32 samples per millisecond, for max 5 milliseconds.
-  int m_samples_left[32 * 5];
-  int m_samples_right[32 * 5];
-  int m_samples_surround[32 * 5];
-  int m_samples_auxA_left[32 * 5];
-  int m_samples_auxA_right[32 * 5];
-  int m_samples_auxA_surround[32 * 5];
-  int m_samples_auxB_left[32 * 5];
-  int m_samples_auxB_right[32 * 5];
-  int m_samples_auxB_surround[32 * 5];
+  int m_samples_left[32 * 5]{};
+  int m_samples_right[32 * 5]{};
+  int m_samples_surround[32 * 5]{};
+  int m_samples_auxA_left[32 * 5]{};
+  int m_samples_auxA_right[32 * 5]{};
+  int m_samples_auxA_surround[32 * 5]{};
+  int m_samples_auxB_left[32 * 5]{};
+  int m_samples_auxB_right[32 * 5]{};
+  int m_samples_auxB_surround[32 * 5]{};
 
-  u16 m_cmdlist[512];
+  u16 m_cmdlist[512]{};
   u32 m_cmdlist_size = 0;
 
   // Table of coefficients for polyphase sample rate conversion.
   // The coefficients aren't always available (they are part of the DSP DROM)
   // so we also need to know if they are valid or not.
   std::optional<u32> m_coeffs_checksum = std::nullopt;
-  std::array<s16, 0x800> m_coeffs;
+  std::array<s16, 0x800> m_coeffs{};
 
   u16 m_compressor_pos = 0;
 
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
index 95e06034e5..7d1baf871d 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
@@ -21,27 +21,27 @@ public:
 
 protected:
   // Additional AUX buffers
-  int m_samples_auxC_left[32 * 3];
-  int m_samples_auxC_right[32 * 3];
-  int m_samples_auxC_surround[32 * 3];
+  int m_samples_auxC_left[32 * 3]{};
+  int m_samples_auxC_right[32 * 3]{};
+  int m_samples_auxC_surround[32 * 3]{};
 
   // Wiimote buffers
-  int m_samples_wm0[6 * 3];
-  int m_samples_aux0[6 * 3];
-  int m_samples_wm1[6 * 3];
-  int m_samples_aux1[6 * 3];
-  int m_samples_wm2[6 * 3];
-  int m_samples_aux2[6 * 3];
-  int m_samples_wm3[6 * 3];
-  int m_samples_aux3[6 * 3];
+  int m_samples_wm0[6 * 3]{};
+  int m_samples_aux0[6 * 3]{};
+  int m_samples_wm1[6 * 3]{};
+  int m_samples_aux1[6 * 3]{};
+  int m_samples_wm2[6 * 3]{};
+  int m_samples_aux2[6 * 3]{};
+  int m_samples_wm3[6 * 3]{};
+  int m_samples_aux3[6 * 3]{};
 
   // Are we implementing an old version of AXWii which still has updates?
-  bool m_old_axwii;
+  bool m_old_axwii = false;
 
   // Last volume values for MAIN and AUX. Used to generate volume ramps to
   // interpolate nicely between old and new volume values.
-  u16 m_last_main_volume;
-  u16 m_last_aux_volumes[3];
+  u16 m_last_main_volume = 0;
+  u16 m_last_aux_volumes[3]{};
 
   // If needed, extract the updates related fields from a PB. We need to
   // reinject them afterwards so that the correct PB typs is written to RAM.
diff --git a/Source/Core/Core/HW/DVD/DVDThread.cpp b/Source/Core/Core/HW/DVD/DVDThread.cpp
index 665557b45f..b06fcd19e2 100644
--- a/Source/Core/Core/HW/DVD/DVDThread.cpp
+++ b/Source/Core/Core/HW/DVD/DVDThread.cpp
@@ -37,26 +37,26 @@ namespace DVDThread
 {
 struct ReadRequest
 {
-  bool copy_to_ram;
-  u32 output_address;
-  u64 dvd_offset;
-  u32 length;
-  DiscIO::Partition partition;
+  bool copy_to_ram = false;
+  u32 output_address = 0;
+  u64 dvd_offset = 0;
+  u32 length = 0;
+  DiscIO::Partition partition{};
 
   // This determines which code DVDInterface will run to reply
   // to the emulated software. We can't use callbacks,
   // because function pointers can't be stored in savestates.
-  DVDInterface::ReplyType reply_type;
+  DVDInterface::ReplyType reply_type = DVDInterface::ReplyType::NoReply;
 
   // IDs are used to uniquely identify a request. They must not be
   // identical to IDs of any other requests that currently exist, but
   // it's fine to re-use IDs of requests that have existed in the past.
-  u64 id;
+  u64 id = 0;
 
   // Only used for logging
-  u64 time_started_ticks;
-  u64 realtime_started_us;
-  u64 realtime_done_us;
+  u64 time_started_ticks = 0;
+  u64 realtime_started_us = 0;
+  u64 realtime_done_us = 0;
 };
 
 using ReadResult = std::pair<ReadRequest, std::vector<u8>>;
diff --git a/Source/Core/Core/HW/EXI/EXI_Device.h b/Source/Core/Core/HW/EXI/EXI_Device.h
index c85bb06c1b..2f0d831af4 100644
--- a/Source/Core/Core/HW/EXI/EXI_Device.h
+++ b/Source/Core/Core/HW/EXI/EXI_Device.h
@@ -65,7 +65,7 @@ public:
   // For savestates. storing it here seemed cleaner than requiring each implementation to report its
   // type. I know this class is set up like an interface, but no code requires it to be strictly
   // such.
-  TEXIDevices m_device_type;
+  TEXIDevices m_device_type = TEXIDevices::EXIDEVICE_NONE;
 
 private:
   // Byte transfer function for this device
diff --git a/Source/Core/Core/HW/EXI/EXI_DeviceEthernet.h b/Source/Core/Core/HW/EXI/EXI_DeviceEthernet.h
index f258a118f8..6d8be1f65b 100644
--- a/Source/Core/Core/HW/EXI/EXI_DeviceEthernet.h
+++ b/Source/Core/Core/HW/EXI/EXI_DeviceEthernet.h
@@ -404,8 +404,8 @@ private:
     defined(__OpenBSD__) || defined(__NetBSD__) || defined(__HAIKU__)
     sf::UdpSocket m_sf_socket;
     sf::IpAddress m_sf_recipient_ip;
-    char m_in_frame[9004];
-    char m_out_frame[9004];
+    char m_in_frame[9004]{};
+    char m_out_frame[9004]{};
     std::thread m_read_thread;
     Common::Flag m_read_enabled;
     Common::Flag m_read_thread_shutdown;
diff --git a/Source/Core/Core/HW/GCMemcard/GCIFile.h b/Source/Core/Core/HW/GCMemcard/GCIFile.h
index d9e9326122..31d25c8c43 100644
--- a/Source/Core/Core/HW/GCMemcard/GCIFile.h
+++ b/Source/Core/Core/HW/GCMemcard/GCIFile.h
@@ -25,7 +25,7 @@ public:
   DEntry m_gci_header;
   std::vector<GCMBlock> m_save_data;
   std::vector<u16> m_used_blocks;
-  bool m_dirty;
+  bool m_dirty = false;
   std::string m_filename;
 };
 }  // namespace Memcard
diff --git a/Source/Core/Core/HW/GCMemcard/GCMemcard.h b/Source/Core/Core/HW/GCMemcard/GCMemcard.h
index 1b965b28a3..6b82d162d2 100644
--- a/Source/Core/Core/HW/GCMemcard/GCMemcard.h
+++ b/Source/Core/Core/HW/GCMemcard/GCMemcard.h
@@ -82,7 +82,7 @@ private:
 struct GCMemcardAnimationFrameRGBA8
 {
   std::vector<u32> image_data;
-  u8 delay;
+  u8 delay = 0;
 };
 
 // size of a single memory card block in bytes
diff --git a/Source/Core/Core/HW/GCMemcard/GCMemcardBase.h b/Source/Core/Core/HW/GCMemcard/GCMemcardBase.h
index b7924801e4..6990148587 100644
--- a/Source/Core/Core/HW/GCMemcard/GCMemcardBase.h
+++ b/Source/Core/Core/HW/GCMemcard/GCMemcardBase.h
@@ -23,10 +23,8 @@ public:
   virtual void ClearAll() = 0;
   virtual void DoState(PointerWrap& p) = 0;
   u32 GetCardId() const { return m_nintendo_card_id; }
-  bool IsAddressInBounds(u32 address) const { return address <= (m_memory_card_size - 1); }
 
 protected:
   int m_card_index;
   u16 m_nintendo_card_id;
-  u32 m_memory_card_size;
 };
diff --git a/Source/Core/Core/HW/GCMemcard/GCMemcardRaw.h b/Source/Core/Core/HW/GCMemcard/GCMemcardRaw.h
index fc8049c873..a8624b64eb 100644
--- a/Source/Core/Core/HW/GCMemcard/GCMemcardRaw.h
+++ b/Source/Core/Core/HW/GCMemcard/GCMemcardRaw.h
@@ -31,6 +31,8 @@ public:
   void DoState(PointerWrap& p) override;
 
 private:
+  bool IsAddressInBounds(u32 address) const { return address <= (m_memory_card_size - 1); }
+
   std::string m_filename;
   std::unique_ptr<u8[]> m_memcard_data;
   std::unique_ptr<u8[]> m_flush_buffer;
@@ -38,4 +40,5 @@ private:
   std::mutex m_flush_mutex;
   Common::Event m_flush_trigger;
   Common::Flag m_dirty;
+  u32 m_memory_card_size;
 };
diff --git a/Source/Core/Core/HW/SI/SI.cpp b/Source/Core/Core/HW/SI/SI.cpp
index 051081fdd0..c55ce4e932 100644
--- a/Source/Core/Core/HW/SI/SI.cpp
+++ b/Source/Core/Core/HW/SI/SI.cpp
@@ -96,9 +96,9 @@ union USIChannelIn_Lo
 // SI Channel
 struct SSIChannel
 {
-  USIChannelOut out;
-  USIChannelIn_Hi in_hi;
-  USIChannelIn_Lo in_lo;
+  USIChannelOut out{};
+  USIChannelIn_Hi in_hi{};
+  USIChannelIn_Lo in_lo{};
   std::unique_ptr<ISIDevice> device;
 
   bool has_recent_device_change = false;
diff --git a/Source/Core/Core/HW/SI/SI_DeviceGBA.h b/Source/Core/Core/HW/SI/SI_DeviceGBA.h
index 663c4c9b1f..0827fa2665 100644
--- a/Source/Core/Core/HW/SI/SI_DeviceGBA.h
+++ b/Source/Core/Core/HW/SI/SI_DeviceGBA.h
@@ -60,7 +60,7 @@ private:
 
   GBASockServer m_sock_server;
   NextAction m_next_action = NextAction::SendCommand;
-  EBufferCommands m_last_cmd;
+  EBufferCommands m_last_cmd = EBufferCommands::CMD_STATUS;
   u64 m_timestamp_sent = 0;
 };
 }  // namespace SerialInterface
diff --git a/Source/Core/Core/HW/WiiSaveStructs.h b/Source/Core/Core/HW/WiiSaveStructs.h
index d5935fade7..e95ce0b6fa 100644
--- a/Source/Core/Core/HW/WiiSaveStructs.h
+++ b/Source/Core/Core/HW/WiiSaveStructs.h
@@ -91,8 +91,9 @@ public:
       File = 1,
       Directory = 2,
     };
-    u8 mode, attributes;
-    Type type;
+    u8 mode = 0;
+    u8 attributes = 0;
+    Type type{};
     /// File name relative to the title data directory.
     std::string path;
     // Only valid for regular (i.e. non-directory) files.
diff --git a/Source/Core/Core/HW/WiimoteCommon/DataReport.h b/Source/Core/Core/HW/WiimoteCommon/DataReport.h
index cdf53d9619..8297424e6a 100644
--- a/Source/Core/Core/HW/WiimoteCommon/DataReport.h
+++ b/Source/Core/Core/HW/WiimoteCommon/DataReport.h
@@ -49,7 +49,7 @@ public:
 
   virtual u32 GetDataSize() const = 0;
 
-  u8* data_ptr;
+  u8* data_ptr = nullptr;
 };
 
 std::unique_ptr<DataReportManipulator> MakeDataReportManipulator(InputReportID rpt_id,
diff --git a/Source/Core/Core/HW/WiimoteEmu/Camera.cpp b/Source/Core/Core/HW/WiimoteEmu/Camera.cpp
index bc87b66ff6..f2a9885fc7 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Camera.cpp
+++ b/Source/Core/Core/HW/WiimoteEmu/Camera.cpp
@@ -94,7 +94,7 @@ void CameraLogic::Update(const Common::Matrix44& transform, Common::Vec2 field_o
   struct CameraPoint
   {
     IRBasic::IRObject position;
-    u8 size;
+    u8 size = 0;
   };
 
   std::array<CameraPoint, leds.size()> camera_points;
diff --git a/Source/Core/Core/HW/WiimoteEmu/Camera.h b/Source/Core/Core/HW/WiimoteEmu/Camera.h
index fa76c8ee71..5c2a186ced 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Camera.h
+++ b/Source/Core/Core/HW/WiimoteEmu/Camera.h
@@ -155,10 +155,10 @@ private:
   int BusRead(u8 slave_addr, u8 addr, int count, u8* data_out) override;
   int BusWrite(u8 slave_addr, u8 addr, int count, const u8* data_in) override;
 
-  Register m_reg_data;
+  Register m_reg_data{};
 
   // When disabled the camera does not respond on the bus.
   // Change is triggered by wiimote report 0x13.
-  bool m_is_enabled;
+  bool m_is_enabled = false;
 };
 }  // namespace WiimoteEmu
diff --git a/Source/Core/Core/HW/WiimoteEmu/Dynamics.cpp b/Source/Core/Core/HW/WiimoteEmu/Dynamics.cpp
index 9c09d1cf0d..f4c31ec7a8 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Dynamics.cpp
+++ b/Source/Core/Core/HW/WiimoteEmu/Dynamics.cpp
@@ -79,10 +79,6 @@ Common::Quaternion ComplementaryFilter(const Common::Quaternion& gyroscope,
   }
 }
 
-IMUCursorState::IMUCursorState() : rotation{Common::Quaternion::Identity()}
-{
-}
-
 void EmulateShake(PositionalState* state, ControllerEmu::Shake* const shake_group,
                   float time_elapsed)
 {
diff --git a/Source/Core/Core/HW/WiimoteEmu/Dynamics.h b/Source/Core/Core/HW/WiimoteEmu/Dynamics.h
index 7a82c319b2..2933fbb7c3 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Dynamics.h
+++ b/Source/Core/Core/HW/WiimoteEmu/Dynamics.h
@@ -23,27 +23,25 @@ using MathUtil::GRAVITY_ACCELERATION;
 struct PositionalState
 {
   // meters
-  Common::Vec3 position;
+  Common::Vec3 position{};
   // meters/second
-  Common::Vec3 velocity;
+  Common::Vec3 velocity{};
   // meters/second^2
-  Common::Vec3 acceleration;
+  Common::Vec3 acceleration{};
 };
 
 struct RotationalState
 {
   // radians
-  Common::Vec3 angle;
+  Common::Vec3 angle{};
   // radians/second
-  Common::Vec3 angular_velocity;
+  Common::Vec3 angular_velocity{};
 };
 
 struct IMUCursorState
 {
-  IMUCursorState();
-
   // Rotation of world around device.
-  Common::Quaternion rotation;
+  Common::Quaternion rotation = Common::Quaternion::Identity();
 
   float recentered_pitch = {};
 };
@@ -51,6 +49,7 @@ struct IMUCursorState
 // Contains both positional and rotational state.
 struct MotionState : PositionalState, RotationalState
 {
+  MotionState() = default;
 };
 
 // Note that 'gyroscope' is rotation of world around device.
diff --git a/Source/Core/Core/HW/WiimoteEmu/Extension/Drums.h b/Source/Core/Core/HW/WiimoteEmu/Extension/Drums.h
index f35e67dc7f..a74013bf32 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Extension/Drums.h
+++ b/Source/Core/Core/HW/WiimoteEmu/Extension/Drums.h
@@ -112,10 +112,10 @@ private:
   ControllerEmu::SettingValue<double> m_hit_strength_setting;
 
   // Holds previous user input state to watch for "new" hits.
-  u8 m_prev_pad_input;
+  u8 m_prev_pad_input = 0;
   // Holds new drum pad hits that still need velocity data to be sent.
-  u8 m_new_pad_hits;
+  u8 m_new_pad_hits = 0;
   // Holds how many more frames to send each drum-pad bit.
-  std::array<u8, 6> m_pad_remaining_frames;
+  std::array<u8, 6> m_pad_remaining_frames{};
 };
 }  // namespace WiimoteEmu
diff --git a/Source/Core/Core/HW/WiimoteEmu/Speaker.h b/Source/Core/Core/HW/WiimoteEmu/Speaker.h
index 09f98d69a0..d2004df459 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Speaker.h
+++ b/Source/Core/Core/HW/WiimoteEmu/Speaker.h
@@ -64,11 +64,11 @@ private:
   int BusRead(u8 slave_addr, u8 addr, int count, u8* data_out) override;
   int BusWrite(u8 slave_addr, u8 addr, int count, const u8* data_in) override;
 
-  Register reg_data;
+  Register reg_data{};
 
   // TODO: What actions reset this state?
   // Is this actually in the register somewhere?
-  ADPCMState adpcm_state;
+  ADPCMState adpcm_state{};
 
   ControllerEmu::SettingValue<double> m_speaker_pan_setting;
 };
diff --git a/Source/Core/Core/HotkeyManager.h b/Source/Core/Core/HotkeyManager.h
index 8f1f37dd10..b214c95a66 100644
--- a/Source/Core/Core/HotkeyManager.h
+++ b/Source/Core/Core/HotkeyManager.h
@@ -232,8 +232,8 @@ public:
   void LoadDefaults(const ControllerInterface& ciface) override;
 
 private:
-  std::array<ControllerEmu::Buttons*, NUM_HOTKEY_GROUPS> m_keys;
-  std::array<ControllerEmu::ControlGroup*, NUM_HOTKEY_GROUPS> m_hotkey_groups;
+  std::array<ControllerEmu::Buttons*, NUM_HOTKEY_GROUPS> m_keys{};
+  std::array<ControllerEmu::ControlGroup*, NUM_HOTKEY_GROUPS> m_hotkey_groups{};
 };
 
 namespace HotkeyManagerEmu
diff --git a/Source/Core/Core/IOS/DI/DI.h b/Source/Core/Core/IOS/DI/DI.h
index 76e36214eb..43645be356 100644
--- a/Source/Core/Core/IOS/DI/DI.h
+++ b/Source/Core/Core/IOS/DI/DI.h
@@ -110,12 +110,9 @@ private:
   struct ExecutingCommandInfo
   {
     ExecutingCommandInfo() {}
-    ExecutingCommandInfo(u32 request_address)
-        : m_request_address(request_address), m_copy_diimmbuf(false)
-    {
-    }
-    u32 m_request_address;
-    bool m_copy_diimmbuf;
+    ExecutingCommandInfo(u32 request_address) : m_request_address(request_address) {}
+    u32 m_request_address = 0;
+    bool m_copy_diimmbuf = false;
   };
 
   friend class ::CBoot;
diff --git a/Source/Core/Core/IOS/ES/ES.h b/Source/Core/Core/IOS/ES/ES.h
index 75ceac887d..2b7e79559f 100644
--- a/Source/Core/Core/IOS/ES/ES.h
+++ b/Source/Core/Core/IOS/ES/ES.h
@@ -377,9 +377,9 @@ private:
   struct OpenedContent
   {
     bool m_opened = false;
-    u64 m_fd;
+    u64 m_fd = 0;
     u64 m_title_id = 0;
-    ES::Content m_content;
+    ES::Content m_content{};
     u32 m_uid = 0;
   };
 
diff --git a/Source/Core/Core/IOS/IOSC.h b/Source/Core/Core/IOS/IOSC.h
index 54b01dfb4e..eca55a752d 100644
--- a/Source/Core/Core/IOS/IOSC.h
+++ b/Source/Core/Core/IOS/IOSC.h
@@ -237,8 +237,8 @@ private:
     void DoState(PointerWrap& p);
 
     bool in_use = false;
-    ObjectType type;
-    ObjectSubType subtype;
+    ObjectType type{};
+    ObjectSubType subtype{};
     std::vector<u8> data;
     u32 misc_data = 0;
     u32 owner_mask = 0;
diff --git a/Source/Core/Core/IOS/Network/NCD/WiiNetConfig.h b/Source/Core/Core/IOS/Network/NCD/WiiNetConfig.h
index 98f0048bd9..6299b0bff0 100644
--- a/Source/Core/Core/IOS/Network/NCD/WiiNetConfig.h
+++ b/Source/Core/Core/IOS/Network/NCD/WiiNetConfig.h
@@ -137,7 +137,7 @@ private:
   };
 #pragma pack(pop)
 
-  ConfigData m_data;
+  ConfigData m_data{};
 };
 }  // namespace Net
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/Network/SSL.h b/Source/Core/Core/IOS/Network/SSL.h
index eee750ed8f..98cb2adf3b 100644
--- a/Source/Core/Core/IOS/Network/SSL.h
+++ b/Source/Core/Core/IOS/Network/SSL.h
@@ -65,18 +65,18 @@ enum SSL_IOCTL
 
 struct WII_SSL
 {
-  mbedtls_ssl_context ctx;
-  mbedtls_ssl_config config;
-  mbedtls_ssl_session session;
-  mbedtls_entropy_context entropy;
-  mbedtls_ctr_drbg_context ctr_drbg;
-  mbedtls_x509_crt cacert;
-  mbedtls_x509_crt clicert;
-  mbedtls_pk_context pk;
+  mbedtls_ssl_context ctx{};
+  mbedtls_ssl_config config{};
+  mbedtls_ssl_session session{};
+  mbedtls_entropy_context entropy{};
+  mbedtls_ctr_drbg_context ctr_drbg{};
+  mbedtls_x509_crt cacert{};
+  mbedtls_x509_crt clicert{};
+  mbedtls_pk_context pk{};
   int sockfd = -1;
   int hostfd = -1;
   std::string hostname;
-  bool active;
+  bool active = false;
 };
 
 class NetSSLDevice : public Device
diff --git a/Source/Core/Core/IOS/Network/Socket.h b/Source/Core/Core/IOS/Network/Socket.h
index f84c84652c..f9555da9e7 100644
--- a/Source/Core/Core/IOS/Network/Socket.h
+++ b/Source/Core/Core/IOS/Network/Socket.h
@@ -233,10 +233,10 @@ public:
 
   struct PollCommand
   {
-    u32 request_addr;
-    u32 buffer_out;
+    u32 request_addr = 0;
+    u32 buffer_out = 0;
     std::vector<pollfd_t> wii_fds;
-    s64 timeout;
+    s64 timeout = 0;
   };
 
   static s32 GetNetErrorCode(s32 ret, std::string_view caller, bool is_rw);
@@ -292,7 +292,7 @@ private:
   void UpdatePollCommands();
 
   std::unordered_map<s32, WiiSocket> WiiSockets;
-  s32 errno_last;
+  s32 errno_last = 0;
   std::vector<PollCommand> pending_polls;
   std::chrono::time_point<std::chrono::high_resolution_clock> last_time =
       std::chrono::high_resolution_clock::now();
diff --git a/Source/Core/Core/IOS/SDIO/SDIOSlot0.h b/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
index 97f6835961..efa6595c78 100644
--- a/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
+++ b/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
@@ -159,7 +159,7 @@ private:
   u32 m_block_length = 0;
   u32 m_bus_width = 0;
 
-  std::array<u32, 0x200 / sizeof(u32)> m_registers;
+  std::array<u32, 0x200 / sizeof(u32)> m_registers{};
 
   File::IOFile m_card;
 };
diff --git a/Source/Core/Core/IOS/WFS/WFSI.h b/Source/Core/Core/IOS/WFS/WFSI.h
index 6a0a065c3b..c83709d386 100644
--- a/Source/Core/Core/IOS/WFS/WFSI.h
+++ b/Source/Core/Core/IOS/WFS/WFSI.h
@@ -50,20 +50,20 @@ private:
 
   std::string m_device_name;
 
-  mbedtls_aes_context m_aes_ctx;
+  mbedtls_aes_context m_aes_ctx{};
   u8 m_aes_key[0x10] = {};
   u8 m_aes_iv[0x10] = {};
 
   ES::TMDReader m_tmd;
   std::string m_base_extract_path;
 
-  u64 m_current_title_id;
+  u64 m_current_title_id = 0;
   std::string m_current_title_id_str;
-  u16 m_current_group_id;
+  u16 m_current_group_id = 0;
   std::string m_current_group_id_str;
-  u64 m_import_title_id;
+  u64 m_import_title_id = 0;
   std::string m_import_title_id_str;
-  u16 m_import_group_id;
+  u16 m_import_group_id = 0;
   std::string m_import_group_id_str;
 
   // Set on IMPORT_TITLE_INIT when the next profile application should not delete
diff --git a/Source/Core/Core/IOS/WFS/WFSSRV.h b/Source/Core/Core/IOS/WFS/WFSSRV.h
index 5c78fa1c3f..cfc6dcc2df 100644
--- a/Source/Core/Core/IOS/WFS/WFSSRV.h
+++ b/Source/Core/Core/IOS/WFS/WFSSRV.h
@@ -84,10 +84,10 @@ private:
 
   struct FileDescriptor
   {
-    bool in_use;
+    bool in_use = false;
     std::string path;
-    int mode;
-    size_t position;
+    int mode = 0;
+    size_t position = 0;
     File::IOFile file;
 
     bool Open();
diff --git a/Source/Core/Core/NetPlayClient.h b/Source/Core/Core/NetPlayClient.h
index 3257ac17cd..3c02cad266 100644
--- a/Source/Core/Core/NetPlayClient.h
+++ b/Source/Core/Core/NetPlayClient.h
@@ -82,11 +82,11 @@ public:
 class Player
 {
 public:
-  PlayerId pid;
+  PlayerId pid{};
   std::string name;
   std::string revision;
-  u32 ping;
-  SyncIdentifierComparison game_status;
+  u32 ping = 0;
+  SyncIdentifierComparison game_status = SyncIdentifierComparison::Unknown;
 
   bool IsHost() const { return pid == 1; }
 };
@@ -153,7 +153,7 @@ protected:
   struct AsyncQueueEntry
   {
     sf::Packet packet;
-    u8 channel_id;
+    u8 channel_id = 0;
   };
 
   void ClearBuffers();
diff --git a/Source/Core/Core/NetPlayProto.h b/Source/Core/Core/NetPlayProto.h
index 537b820701..87af1fe26c 100644
--- a/Source/Core/Core/NetPlayProto.h
+++ b/Source/Core/Core/NetPlayProto.h
@@ -28,84 +28,84 @@ namespace NetPlay
 {
 struct NetSettings
 {
-  bool m_CPUthread;
-  PowerPC::CPUCore m_CPUcore;
-  bool m_EnableCheats;
-  int m_SelectedLanguage;
-  bool m_OverrideRegionSettings;
-  bool m_DSPHLE;
-  bool m_DSPEnableJIT;
-  bool m_WriteToMemcard;
-  bool m_RAMOverrideEnable;
-  u32 m_Mem1Size;
-  u32 m_Mem2Size;
-  DiscIO::Region m_FallbackRegion;
-  bool m_AllowSDWrites;
-  bool m_CopyWiiSave;
-  bool m_OCEnable;
-  float m_OCFactor;
-  std::array<ExpansionInterface::TEXIDevices, 3> m_EXIDevice;
+  bool m_CPUthread = false;
+  PowerPC::CPUCore m_CPUcore{};
+  bool m_EnableCheats = false;
+  int m_SelectedLanguage = 0;
+  bool m_OverrideRegionSettings = false;
+  bool m_DSPHLE = false;
+  bool m_DSPEnableJIT = false;
+  bool m_WriteToMemcard = false;
+  bool m_RAMOverrideEnable = false;
+  u32 m_Mem1Size = 0;
+  u32 m_Mem2Size = 0;
+  DiscIO::Region m_FallbackRegion{};
+  bool m_AllowSDWrites = false;
+  bool m_CopyWiiSave = false;
+  bool m_OCEnable = false;
+  float m_OCFactor = 0;
+  std::array<ExpansionInterface::TEXIDevices, 3> m_EXIDevice{};
 
-  std::array<u32, Config::SYSCONF_SETTINGS.size()> m_SYSCONFSettings;
+  std::array<u32, Config::SYSCONF_SETTINGS.size()> m_SYSCONFSettings{};
 
-  bool m_EFBAccessEnable;
-  bool m_BBoxEnable;
-  bool m_ForceProgressive;
-  bool m_EFBToTextureEnable;
-  bool m_XFBToTextureEnable;
-  bool m_DisableCopyToVRAM;
-  bool m_ImmediateXFBEnable;
-  bool m_EFBEmulateFormatChanges;
-  int m_SafeTextureCacheColorSamples;
-  bool m_PerfQueriesEnable;
-  bool m_FloatExceptions;
-  bool m_DivideByZeroExceptions;
-  bool m_FPRF;
-  bool m_AccurateNaNs;
-  bool m_DisableICache;
-  bool m_SyncOnSkipIdle;
-  bool m_SyncGPU;
-  int m_SyncGpuMaxDistance;
-  int m_SyncGpuMinDistance;
-  float m_SyncGpuOverclock;
-  bool m_JITFollowBranch;
-  bool m_FastDiscSpeed;
-  bool m_MMU;
-  bool m_Fastmem;
-  bool m_SkipIPL;
-  bool m_LoadIPLDump;
-  bool m_VertexRounding;
-  int m_InternalResolution;
-  bool m_EFBScaledCopy;
-  bool m_FastDepthCalc;
-  bool m_EnablePixelLighting;
-  bool m_WidescreenHack;
-  bool m_ForceFiltering;
-  int m_MaxAnisotropy;
-  bool m_ForceTrueColor;
-  bool m_DisableCopyFilter;
-  bool m_DisableFog;
-  bool m_ArbitraryMipmapDetection;
-  float m_ArbitraryMipmapDetectionThreshold;
-  bool m_EnableGPUTextureDecoding;
-  bool m_DeferEFBCopies;
-  int m_EFBAccessTileSize;
-  bool m_EFBAccessDeferInvalidation;
+  bool m_EFBAccessEnable = false;
+  bool m_BBoxEnable = false;
+  bool m_ForceProgressive = false;
+  bool m_EFBToTextureEnable = false;
+  bool m_XFBToTextureEnable = false;
+  bool m_DisableCopyToVRAM = false;
+  bool m_ImmediateXFBEnable = false;
+  bool m_EFBEmulateFormatChanges = false;
+  int m_SafeTextureCacheColorSamples = 0;
+  bool m_PerfQueriesEnable = false;
+  bool m_FloatExceptions = false;
+  bool m_DivideByZeroExceptions = false;
+  bool m_FPRF = false;
+  bool m_AccurateNaNs = false;
+  bool m_DisableICache = false;
+  bool m_SyncOnSkipIdle = false;
+  bool m_SyncGPU = false;
+  int m_SyncGpuMaxDistance = 0;
+  int m_SyncGpuMinDistance = 0;
+  float m_SyncGpuOverclock = 0;
+  bool m_JITFollowBranch = false;
+  bool m_FastDiscSpeed = false;
+  bool m_MMU = false;
+  bool m_Fastmem = false;
+  bool m_SkipIPL = false;
+  bool m_LoadIPLDump = false;
+  bool m_VertexRounding = false;
+  int m_InternalResolution = 0;
+  bool m_EFBScaledCopy = false;
+  bool m_FastDepthCalc = false;
+  bool m_EnablePixelLighting = false;
+  bool m_WidescreenHack = false;
+  bool m_ForceFiltering = false;
+  int m_MaxAnisotropy = 0;
+  bool m_ForceTrueColor = false;
+  bool m_DisableCopyFilter = false;
+  bool m_DisableFog = false;
+  bool m_ArbitraryMipmapDetection = false;
+  float m_ArbitraryMipmapDetectionThreshold = 0;
+  bool m_EnableGPUTextureDecoding = false;
+  bool m_DeferEFBCopies = false;
+  int m_EFBAccessTileSize = 0;
+  bool m_EFBAccessDeferInvalidation = false;
 
-  bool m_StrictSettingsSync;
-  bool m_SyncSaveData;
-  bool m_SyncCodes;
+  bool m_StrictSettingsSync = false;
+  bool m_SyncSaveData = false;
+  bool m_SyncCodes = false;
   std::string m_SaveDataRegion;
-  bool m_SyncAllWiiSaves;
-  std::array<int, 4> m_WiimoteExtension;
-  bool m_GolfMode;
-  bool m_UseFMA;
-  bool m_HideRemoteGBAs;
+  bool m_SyncAllWiiSaves = false;
+  std::array<int, 4> m_WiimoteExtension{};
+  bool m_GolfMode = false;
+  bool m_UseFMA = false;
+  bool m_HideRemoteGBAs = false;
 
   // These aren't sent over the network directly
-  bool m_IsHosting;
-  bool m_HostInputAuthority;
-  std::array<std::string, 4> m_GBARomPaths;
+  bool m_IsHosting = false;
+  bool m_HostInputAuthority = false;
+  std::array<std::string, 4> m_GBARomPaths{};
 };
 
 struct NetTraversalConfig
@@ -226,7 +226,7 @@ enum : u8
 
 struct WiimoteInput
 {
-  u8 report_id;
+  u8 report_id = 0;
   std::vector<u8> data;
 };
 using PlayerId = u8;
@@ -235,19 +235,19 @@ using PadIndex = s8;
 using PadMappingArray = std::array<PlayerId, 4>;
 struct GBAConfig
 {
-  bool enabled;
-  bool has_rom;
+  bool enabled = false;
+  bool has_rom = false;
   std::string title;
-  std::array<u8, 20> hash;
+  std::array<u8, 20> hash{};
 };
 using GBAConfigArray = std::array<GBAConfig, 4>;
 
 struct PadDetails
 {
-  std::string player_name;
-  bool is_local;
-  int local_pad;
-  bool hide_gba;
+  std::string player_name{};
+  bool is_local = false;
+  int local_pad = 0;
+  bool hide_gba = false;
 };
 
 std::string GetPlayerMappingString(PlayerId pid, const PadMappingArray& pad_map,
diff --git a/Source/Core/Core/NetPlayServer.h b/Source/Core/Core/NetPlayServer.h
index 76c1d7ae94..67de180204 100644
--- a/Source/Core/Core/NetPlayServer.h
+++ b/Source/Core/Core/NetPlayServer.h
@@ -80,16 +80,16 @@ private:
   class Client
   {
   public:
-    PlayerId pid;
+    PlayerId pid{};
     std::string name;
     std::string revision;
-    SyncIdentifierComparison game_status;
-    bool has_ipl_dump;
-    bool has_hardware_fma;
+    SyncIdentifierComparison game_status = SyncIdentifierComparison::Unknown;
+    bool has_ipl_dump = false;
+    bool has_hardware_fma = false;
 
-    ENetPeer* socket;
-    u32 ping;
-    u32 current_game;
+    ENetPeer* socket = nullptr;
+    u32 ping = 0;
+    u32 current_game = 0;
 
     Common::QoSSession qos_session;
 
@@ -106,16 +106,16 @@ private:
   struct AsyncQueueEntry
   {
     sf::Packet packet;
-    PlayerId target_pid;
-    TargetMode target_mode;
-    u8 channel_id;
+    PlayerId target_pid{};
+    TargetMode target_mode{};
+    u8 channel_id = 0;
   };
 
   struct ChunkedDataQueueEntry
   {
     sf::Packet packet;
-    PlayerId target_pid;
-    TargetMode target_mode;
+    PlayerId target_pid{};
+    TargetMode target_mode{};
     std::string title;
   };
 
@@ -171,7 +171,7 @@ private:
   std::map<PlayerId, Client> m_players;
 
   std::unordered_map<u32, std::vector<std::pair<PlayerId, u64>>> m_timebase_by_frame;
-  bool m_desync_detected;
+  bool m_desync_detected = false;
 
   struct
   {
@@ -191,7 +191,7 @@ private:
   Common::Event m_chunked_data_event;
   Common::Event m_chunked_data_complete_event;
   std::thread m_chunked_data_thread;
-  u32 m_next_chunked_data_id;
+  u32 m_next_chunked_data_id = 0;
   std::unordered_map<u32, unsigned int> m_chunked_data_complete_count;
   bool m_abort_chunked_data = false;
 
diff --git a/Source/Core/Core/PowerPC/Jit64/Jit.h b/Source/Core/Core/PowerPC/Jit64/Jit.h
index 70c53bd784..2e5b4949db 100644
--- a/Source/Core/Core/PowerPC/Jit64/Jit.h
+++ b/Source/Core/Core/PowerPC/Jit64/Jit.h
@@ -266,9 +266,9 @@ private:
 
   Jit64AsmRoutineManager asm_routines{*this};
 
-  bool m_enable_blr_optimization;
-  bool m_cleanup_after_stackfault;
-  u8* m_stack;
+  bool m_enable_blr_optimization = false;
+  bool m_cleanup_after_stackfault = false;
+  u8* m_stack = nullptr;
 
   HyoutaUtilities::RangeSizeSet<u8*> m_free_ranges_near;
   HyoutaUtilities::RangeSizeSet<u8*> m_free_ranges_far;
diff --git a/Source/Core/Core/PowerPC/Jit64Common/EmuCodeBlock.h b/Source/Core/Core/PowerPC/Jit64Common/EmuCodeBlock.h
index 330ba7f4ae..1340633578 100644
--- a/Source/Core/Core/PowerPC/Jit64Common/EmuCodeBlock.h
+++ b/Source/Core/Core/PowerPC/Jit64Common/EmuCodeBlock.h
@@ -134,9 +134,9 @@ protected:
   FarCodeCache m_far_code;
 
   // Backed up when we switch to far code.
-  u8* m_near_code;
-  u8* m_near_code_end;
-  bool m_near_code_write_failed;
+  u8* m_near_code = nullptr;
+  u8* m_near_code_end = nullptr;
+  bool m_near_code_write_failed = false;
 
   std::unordered_map<u8*, TrampolineInfo> m_back_patch_info;
   std::unordered_map<u8*, u8*> m_exception_handler_at_loc;
diff --git a/Source/Core/Core/PowerPC/JitCommon/JitCache.h b/Source/Core/Core/PowerPC/JitCommon/JitCache.h
index c9e3f02d91..f2c0719109 100644
--- a/Source/Core/Core/PowerPC/JitCommon/JitCache.h
+++ b/Source/Core/Core/PowerPC/JitCommon/JitCache.h
@@ -205,5 +205,5 @@ private:
 
   // This array is indexed with the masked PC and likely holds the correct block id.
   // This is used as a fast cache of block_map used in the assembly dispatcher.
-  std::array<JitBlock*, FAST_BLOCK_MAP_ELEMENTS> fast_block_map;  // start_addr & mask -> number
+  std::array<JitBlock*, FAST_BLOCK_MAP_ELEMENTS> fast_block_map{};  // start_addr & mask -> number
 };
diff --git a/Source/Core/Core/PowerPC/PPCAnalyst.h b/Source/Core/Core/PowerPC/PPCAnalyst.h
index 223f07bb7b..4dfd043f41 100644
--- a/Source/Core/Core/PowerPC/PPCAnalyst.h
+++ b/Source/Core/Core/PowerPC/PPCAnalyst.h
@@ -24,29 +24,29 @@ namespace PPCAnalyst
 struct CodeOp  // 16B
 {
   UGeckoInstruction inst;
-  GekkoOPInfo* opinfo;
-  u32 address;
-  u32 branchTo;  // if UINT32_MAX, not a branch
+  GekkoOPInfo* opinfo = nullptr;
+  u32 address = 0;
+  u32 branchTo = 0;  // if UINT32_MAX, not a branch
   BitSet32 regsOut;
   BitSet32 regsIn;
   BitSet32 fregsIn;
-  s8 fregOut;
-  bool isBranchTarget;
-  bool branchUsesCtr;
-  bool branchIsIdleLoop;
-  bool wantsCR0;
-  bool wantsCR1;
-  bool wantsFPRF;
-  bool wantsCA;
-  bool wantsCAInFlags;
-  bool outputCR0;
-  bool outputCR1;
-  bool outputFPRF;
-  bool outputCA;
-  bool canEndBlock;
-  bool canCauseException;
-  bool skipLRStack;
-  bool skip;  // followed BL-s for example
+  s8 fregOut = 0;
+  bool isBranchTarget = false;
+  bool branchUsesCtr = false;
+  bool branchIsIdleLoop = false;
+  bool wantsCR0 = false;
+  bool wantsCR1 = false;
+  bool wantsFPRF = false;
+  bool wantsCA = false;
+  bool wantsCAInFlags = false;
+  bool outputCR0 = false;
+  bool outputCR1 = false;
+  bool outputFPRF = false;
+  bool outputCA = false;
+  bool canEndBlock = false;
+  bool canCauseException = false;
+  bool skipLRStack = false;
+  bool skip = false;  // followed BL-s for example
   // which registers are still needed after this instruction in this block
   BitSet32 fprInUse;
   BitSet32 gprInUse;
@@ -138,23 +138,24 @@ using CodeBuffer = std::vector<CodeOp>;
 struct CodeBlock
 {
   // Beginning PPC address.
-  u32 m_address;
+  u32 m_address = 0;
 
   // Number of instructions
   // Gives us the size of the block.
-  u32 m_num_instructions;
+  u32 m_num_instructions = 0;
 
   // Some basic statistics about the block.
-  BlockStats* m_stats;
+  BlockStats* m_stats = nullptr;
 
   // Register statistics about the block.
-  BlockRegStats *m_gpa, *m_fpa;
+  BlockRegStats* m_gpa = nullptr;
+  BlockRegStats* m_fpa = nullptr;
 
   // Are we a broken block?
-  bool m_broken;
+  bool m_broken = false;
 
   // Did we have a memory_exception?
-  bool m_memory_exception;
+  bool m_memory_exception = false;
 
   // Which GQRs this block uses, if any.
   BitSet8 m_gqr_used;
diff --git a/Source/Core/Core/PowerPC/PPCCache.cpp b/Source/Core/Core/PowerPC/PPCCache.cpp
index 2e0ccd7159..181764dc3b 100644
--- a/Source/Core/Core/PowerPC/PPCCache.cpp
+++ b/Source/Core/Core/PowerPC/PPCCache.cpp
@@ -87,10 +87,6 @@ constexpr std::array<u32, 128> s_way_from_plru = [] {
 }();
 }  // Anonymous namespace
 
-InstructionCache::InstructionCache()
-{
-}
-
 void InstructionCache::Reset()
 {
   valid.fill(0);
diff --git a/Source/Core/Core/PowerPC/PPCCache.h b/Source/Core/Core/PowerPC/PPCCache.h
index 1bb0f8877e..fdc23ba546 100644
--- a/Source/Core/Core/PowerPC/PPCCache.h
+++ b/Source/Core/Core/PowerPC/PPCCache.h
@@ -21,16 +21,16 @@ constexpr u32 ICACHE_VMEM_BIT = 0x20000000;
 
 struct InstructionCache
 {
-  std::array<std::array<std::array<u32, ICACHE_BLOCK_SIZE>, ICACHE_WAYS>, ICACHE_SETS> data;
-  std::array<std::array<u32, ICACHE_WAYS>, ICACHE_SETS> tags;
-  std::array<u32, ICACHE_SETS> plru;
-  std::array<u32, ICACHE_SETS> valid;
+  std::array<std::array<std::array<u32, ICACHE_BLOCK_SIZE>, ICACHE_WAYS>, ICACHE_SETS> data{};
+  std::array<std::array<u32, ICACHE_WAYS>, ICACHE_SETS> tags{};
+  std::array<u32, ICACHE_SETS> plru{};
+  std::array<u32, ICACHE_SETS> valid{};
 
-  std::array<u8, 1 << 20> lookup_table;
-  std::array<u8, 1 << 21> lookup_table_ex;
-  std::array<u8, 1 << 20> lookup_table_vmem;
+  std::array<u8, 1 << 20> lookup_table{};
+  std::array<u8, 1 << 21> lookup_table_ex{};
+  std::array<u8, 1 << 20> lookup_table_vmem{};
 
-  InstructionCache();
+  InstructionCache() = default;
   u32 ReadInstruction(u32 addr);
   void Invalidate(u32 addr);
   void Init();
diff --git a/Source/Core/Core/PowerPC/PowerPC.h b/Source/Core/Core/PowerPC/PowerPC.h
index 33566908b9..ea05fdcd01 100644
--- a/Source/Core/Core/PowerPC/PowerPC.h
+++ b/Source/Core/Core/PowerPC/PowerPC.h
@@ -113,14 +113,14 @@ static_assert(std::is_standard_layout<PairedSingle>(), "PairedSingle must be sta
 // Unfortunately not all of those fit in 520 bytes, but we can fit most of ps and all of the rest.
 struct PowerPCState
 {
-  u32 pc;  // program counter
-  u32 npc;
+  u32 pc = 0;  // program counter
+  u32 npc = 0;
 
   // gather pipe pointer for JIT access
-  u8* gather_pipe_ptr;
-  u8* gather_pipe_base_ptr;
+  u8* gather_pipe_ptr = nullptr;
+  u8* gather_pipe_base_ptr = nullptr;
 
-  u32 gpr[32];  // General purpose registers. r1 = stack pointer.
+  u32 gpr[32]{};  // General purpose registers. r1 = stack pointer.
 
 #ifndef _M_X86_64
   // The paired singles are strange : PS0 is stored in the full 64 bits of each FPR
@@ -129,25 +129,25 @@ struct PowerPCState
   alignas(16) PairedSingle ps[32];
 #endif
 
-  ConditionRegister cr;
+  ConditionRegister cr{};
 
   UReg_MSR msr;      // machine state register
   UReg_FPSCR fpscr;  // floating point flags/status bits
 
   // Exception management.
-  u32 Exceptions;
+  u32 Exceptions = 0;
 
   // Downcount for determining when we need to do timing
   // This isn't quite the right location for it, but it is here to accelerate the ARM JIT
   // This variable should be inside of the CoreTiming namespace if we wanted to be correct.
-  int downcount;
+  int downcount = 0;
 
   // XER, reformatted into byte fields for easier access.
-  u8 xer_ca;
-  u8 xer_so_ov;  // format: (SO << 1) | OV
+  u8 xer_ca = 0;
+  u8 xer_so_ov = 0;  // format: (SO << 1) | OV
   // The Broadway CPU implements bits 16-23 of the XER register... even though it doesn't support
   // lscbx
-  u16 xer_stringctrl;
+  u16 xer_stringctrl = 0;
 
 #if _M_X86_64
   // This member exists only for the purpose of an assertion that its offset <= 0x100.
@@ -156,19 +156,19 @@ struct PowerPCState
   alignas(16) PairedSingle ps[32];
 #endif
 
-  u32 sr[16];  // Segment registers.
+  u32 sr[16]{};  // Segment registers.
 
   // special purpose registers - controls quantizers, DMA, and lots of other misc extensions.
   // also for power management, but we don't care about that.
-  u32 spr[1024];
+  u32 spr[1024]{};
 
   // Storage for the stack pointer of the BLR optimization.
-  u8* stored_stack_pointer;
+  u8* stored_stack_pointer = nullptr;
 
   std::array<std::array<TLBEntry, TLB_SIZE / TLB_WAYS>, NUM_TLBS> tlb;
 
-  u32 pagetable_base;
-  u32 pagetable_hashmask;
+  u32 pagetable_base = 0;
+  u32 pagetable_hashmask = 0;
 
   InstructionCache iCache;
 
diff --git a/Source/Core/Core/PowerPC/Profiler.h b/Source/Core/Core/PowerPC/Profiler.h
index c7853c1534..3c4b3eb33b 100644
--- a/Source/Core/Core/PowerPC/Profiler.h
+++ b/Source/Core/Core/PowerPC/Profiler.h
@@ -28,9 +28,9 @@ struct BlockStat
 struct ProfileStats
 {
   std::vector<BlockStat> block_stats;
-  u64 cost_sum;
-  u64 timecost_sum;
-  u64 countsPerSec;
+  u64 cost_sum = 0;
+  u64 timecost_sum = 0;
+  u64 countsPerSec = 0;
 };
 
 }  // namespace Profiler
diff --git a/Source/Core/Core/State.cpp b/Source/Core/Core/State.cpp
index 729a60b993..86877ecb50 100644
--- a/Source/Core/Core/State.cpp
+++ b/Source/Core/Core/State.cpp
@@ -298,10 +298,10 @@ static std::map<double, int> GetSavedStates()
 
 struct CompressAndDumpState_args
 {
-  std::vector<u8>* buffer_vector;
-  std::mutex* buffer_mutex;
+  std::vector<u8>* buffer_vector = nullptr;
+  std::mutex* buffer_mutex = nullptr;
   std::string filename;
-  bool wait;
+  bool wait = false;
 };
 
 static void CompressAndDumpState(CompressAndDumpState_args save_args)
diff --git a/Source/Core/Core/SyncIdentifier.h b/Source/Core/Core/SyncIdentifier.h
index 9be190943c..7175f073c4 100644
--- a/Source/Core/Core/SyncIdentifier.h
+++ b/Source/Core/Core/SyncIdentifier.h
@@ -13,18 +13,18 @@ namespace NetPlay
 {
 struct SyncIdentifier
 {
-  u64 dol_elf_size;
+  u64 dol_elf_size = 0;
   std::string game_id;
-  u16 revision;
-  u8 disc_number;
-  bool is_datel;
+  u16 revision = 0;
+  u8 disc_number = 0;
+  bool is_datel = false;
 
   // This hash is intended to be (but is not guaranteed to be):
   // 1. Identical for discs with no differences that affect netplay/TAS sync
   // 2. Different for discs with differences that affect netplay/TAS sync
   // 3. Much faster than hashing the entire disc
   // The way the hash is calculated may change with updates to Dolphin.
-  std::array<u8, 20> sync_hash;
+  std::array<u8, 20> sync_hash{};
 
   bool operator==(const SyncIdentifier& s) const
   {
diff --git a/Source/Core/DiscIO/CompressedBlob.cpp b/Source/Core/DiscIO/CompressedBlob.cpp
index c39dbc64bf..70d123ccf3 100644
--- a/Source/Core/DiscIO/CompressedBlob.cpp
+++ b/Source/Core/DiscIO/CompressedBlob.cpp
@@ -173,17 +173,17 @@ struct CompressThreadState
 
 struct CompressParameters
 {
-  std::vector<u8> data;
-  u32 block_number;
-  u64 inpos;
+  std::vector<u8> data{};
+  u32 block_number = 0;
+  u64 inpos = 0;
 };
 
 struct OutputParameters
 {
-  std::vector<u8> data;
-  u32 block_number;
-  bool compressed;
-  u64 inpos;
+  std::vector<u8> data{};
+  u32 block_number = 0;
+  bool compressed = false;
+  u64 inpos = 0;
 };
 
 static ConversionResultCode SetUpCompressThreadState(CompressThreadState* state)
diff --git a/Source/Core/DiscIO/DirectoryBlob.h b/Source/Core/DiscIO/DirectoryBlob.h
index 1ec5372fa4..e4eb1b3cd3 100644
--- a/Source/Core/DiscIO/DirectoryBlob.h
+++ b/Source/Core/DiscIO/DirectoryBlob.h
@@ -132,14 +132,14 @@ private:
   std::vector<u8> m_apploader;
   std::vector<u8> m_fst_data;
 
-  std::array<u8, VolumeWii::AES_KEY_SIZE> m_key;
+  std::array<u8, VolumeWii::AES_KEY_SIZE> m_key{};
 
   std::string m_root_directory;
   bool m_is_wii = false;
   // GameCube has no shift, Wii has 2 bit shift
   u32 m_address_shift = 0;
 
-  u64 m_data_size;
+  u64 m_data_size = 0;
 };
 
 class DirectoryBlobReader : public BlobReader
diff --git a/Source/Core/DiscIO/DiscScrubber.h b/Source/Core/DiscIO/DiscScrubber.h
index 35135bea61..72d50bf402 100644
--- a/Source/Core/DiscIO/DiscScrubber.h
+++ b/Source/Core/DiscIO/DiscScrubber.h
@@ -46,7 +46,7 @@ private:
   bool ParsePartitionData(const Partition& partition);
   void ParseFileSystemData(u64 partition_data_offset, const FileInfo& directory);
 
-  const Volume* m_disc;
+  const Volume* m_disc = nullptr;
 
   std::vector<u8> m_free_table;
   u64 m_file_size = 0;
diff --git a/Source/Core/DiscIO/LaggedFibonacciGenerator.h b/Source/Core/DiscIO/LaggedFibonacciGenerator.h
index d4b3a51cc4..2eace618aa 100644
--- a/Source/Core/DiscIO/LaggedFibonacciGenerator.h
+++ b/Source/Core/DiscIO/LaggedFibonacciGenerator.h
@@ -43,7 +43,7 @@ private:
   static constexpr size_t LFG_K = 521;
   static constexpr size_t LFG_J = 32;
 
-  std::array<u32, LFG_K> m_buffer;
+  std::array<u32, LFG_K> m_buffer{};
 
   size_t m_position_bytes = 0;
 };
diff --git a/Source/Core/DiscIO/VolumeVerifier.h b/Source/Core/DiscIO/VolumeVerifier.h
index a6fea8f76b..6e573880ac 100644
--- a/Source/Core/DiscIO/VolumeVerifier.h
+++ b/Source/Core/DiscIO/VolumeVerifier.h
@@ -78,7 +78,7 @@ private:
 
   struct PotentialMatch
   {
-    u64 size;
+    u64 size = 0;
     Hashes<std::vector<u8>> hashes;
   };
 
@@ -87,9 +87,9 @@ private:
   std::vector<PotentialMatch> ScanDatfile(const std::vector<u8>& data, const std::string& system);
 
   std::string m_game_id;
-  u16 m_revision;
-  u8 m_disc_number;
-  u64 m_size;
+  u16 m_revision = 0;
+  u8 m_disc_number = 0;
+  u64 m_size = 0;
 
   std::future<std::vector<PotentialMatch>> m_future;
   Result m_result;
@@ -173,8 +173,8 @@ private:
   Hashes<bool> m_hashes_to_calculate{};
   bool m_calculating_any_hash = false;
   unsigned long m_crc32_context = 0;
-  mbedtls_md5_context m_md5_context;
-  mbedtls_sha1_context m_sha1_context;
+  mbedtls_md5_context m_md5_context{};
+  mbedtls_sha1_context m_sha1_context{};
 
   u64 m_excess_bytes = 0;
   std::vector<u8> m_data;
diff --git a/Source/Core/DiscIO/VolumeWii.h b/Source/Core/DiscIO/VolumeWii.h
index 1e89e63e92..f2dea1b016 100644
--- a/Source/Core/DiscIO/VolumeWii.h
+++ b/Source/Core/DiscIO/VolumeWii.h
@@ -122,7 +122,7 @@ private:
     Common::Lazy<std::vector<u8>> h3_table;
     Common::Lazy<std::unique_ptr<FileSystem>> file_system;
     Common::Lazy<u64> data_offset;
-    u32 type;
+    u32 type = 0;
   };
 
   std::unique_ptr<BlobReader> m_reader;
@@ -131,7 +131,7 @@ private:
   bool m_encrypted;
 
   mutable u64 m_last_decrypted_block;
-  mutable u8 m_last_decrypted_block_data[BLOCK_DATA_SIZE];
+  mutable u8 m_last_decrypted_block_data[BLOCK_DATA_SIZE]{};
 };
 
 }  // namespace DiscIO
diff --git a/Source/Core/DiscIO/WIABlob.h b/Source/Core/DiscIO/WIABlob.h
index 88db70a210..d13476762b 100644
--- a/Source/Core/DiscIO/WIABlob.h
+++ b/Source/Core/DiscIO/WIABlob.h
@@ -168,7 +168,10 @@ private:
     bool is_partition;
     u8 partition_data_index;
 
-    DataEntry(size_t index_) : index(static_cast<u32>(index_)), is_partition(false) {}
+    DataEntry(size_t index_)
+        : index(static_cast<u32>(index_)), is_partition(false), partition_data_index(0)
+    {
+    }
     DataEntry(size_t index_, size_t partition_data_index_)
         : index(static_cast<u32>(index_)), is_partition(true),
           partition_data_index(static_cast<u8>(partition_data_index_))
@@ -281,11 +284,11 @@ private:
 
   struct CompressParameters
   {
-    std::vector<u8> data;
-    const DataEntry* data_entry;
-    u64 data_offset;
-    u64 bytes_read;
-    size_t group_index;
+    std::vector<u8> data{};
+    const DataEntry* data_entry = nullptr;
+    u64 data_offset = 0;
+    u64 bytes_read = 0;
+    size_t group_index = 0;
   };
 
   struct WIAOutputParametersEntry
@@ -312,8 +315,8 @@ private:
   struct OutputParameters
   {
     std::vector<OutputParametersEntry> entries;
-    u64 bytes_read;
-    size_t group_index;
+    u64 bytes_read = 0;
+    size_t group_index = 0;
   };
 
   static bool PadTo4(File::IOFile* file, u64* bytes_written);
diff --git a/Source/Core/DiscIO/WIACompression.h b/Source/Core/DiscIO/WIACompression.h
index df5e9dacba..fdabedbed0 100644
--- a/Source/Core/DiscIO/WIACompression.h
+++ b/Source/Core/DiscIO/WIACompression.h
@@ -141,7 +141,7 @@ private:
   u32 m_rvz_packed_size;
 
   u32 m_size = 0;
-  bool m_junk;
+  bool m_junk = false;
   LaggedFibonacciGenerator m_lfg;
 };
 
@@ -178,7 +178,7 @@ public:
 
 private:
   std::vector<u8> m_buffer;
-  size_t m_bytes_written;
+  size_t m_bytes_written = 0;
   mbedtls_sha1_context m_sha1_context;
 };
 
@@ -244,7 +244,7 @@ private:
   void ExpandBuffer(size_t bytes_to_add);
 
   ZSTD_CStream* m_stream;
-  ZSTD_outBuffer m_out_buffer;
+  ZSTD_outBuffer m_out_buffer{};
   std::vector<u8> m_buffer;
 };
 
diff --git a/Source/Core/DiscIO/WiiEncryptionCache.h b/Source/Core/DiscIO/WiiEncryptionCache.h
index 629daff2bb..3516d3b538 100644
--- a/Source/Core/DiscIO/WiiEncryptionCache.h
+++ b/Source/Core/DiscIO/WiiEncryptionCache.h
@@ -50,7 +50,7 @@ public:
 private:
   BlobReader* m_blob;
   std::unique_ptr<std::array<u8, VolumeWii::GROUP_TOTAL_SIZE>> m_cache;
-  u64 m_cached_offset;
+  u64 m_cached_offset = 0;
 };
 
 }  // namespace DiscIO
diff --git a/Source/Core/DolphinQt/Config/Graphics/PostProcessingConfigWindow.h b/Source/Core/DolphinQt/Config/Graphics/PostProcessingConfigWindow.h
index 0117c05b8b..4b37380c34 100644
--- a/Source/Core/DolphinQt/Config/Graphics/PostProcessingConfigWindow.h
+++ b/Source/Core/DolphinQt/Config/Graphics/PostProcessingConfigWindow.h
@@ -52,7 +52,7 @@ private:
     u32 AddInteger(PostProcessingConfigWindow* parent, QGridLayout* grid, u32 row);
     u32 AddFloat(PostProcessingConfigWindow* parent, QGridLayout* grid, u32 row);
 
-    QCheckBox* m_checkbox;
+    QCheckBox* m_checkbox = nullptr;
     std::vector<QSlider*> m_sliders;
     std::vector<QLineEdit*> m_value_boxes;
 
diff --git a/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp b/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp
index 659b6a889f..6e178a2ed8 100644
--- a/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp
@@ -207,7 +207,7 @@ public:
 
 private:
   std::function<ControlState()> m_state_evaluator;
-  bool m_should_paint_state_indicator;
+  bool m_should_paint_state_indicator = false;
 };
 
 IOWindow::IOWindow(MappingWidget* parent, ControllerEmu::EmulatedController* controller,
diff --git a/Source/Core/DolphinQt/Debugger/CodeViewWidget.cpp b/Source/Core/DolphinQt/Debugger/CodeViewWidget.cpp
index 0b571e9502..a2b113f881 100644
--- a/Source/Core/DolphinQt/Debugger/CodeViewWidget.cpp
+++ b/Source/Core/DolphinQt/Debugger/CodeViewWidget.cpp
@@ -35,10 +35,10 @@
 
 struct CodeViewBranch
 {
-  u32 src_addr;
-  u32 dst_addr;
+  u32 src_addr = 0;
+  u32 dst_addr = 0;
   u32 indentation = 0;
-  bool is_link;
+  bool is_link = false;
 };
 
 constexpr u32 WIDTH_PER_BRANCH_ARROW = 16;
diff --git a/Source/Core/DolphinQt/TAS/TASCheckBox.h b/Source/Core/DolphinQt/TAS/TASCheckBox.h
index 04d3b3001c..afec671194 100644
--- a/Source/Core/DolphinQt/TAS/TASCheckBox.h
+++ b/Source/Core/DolphinQt/TAS/TASCheckBox.h
@@ -21,7 +21,7 @@ protected:
 
 private:
   const TASInputWindow* m_parent;
-  int m_frame_turbo_started;
-  int m_turbo_press_frames;
-  int m_turbo_total_frames;
+  int m_frame_turbo_started = 0;
+  int m_turbo_press_frames = 0;
+  int m_turbo_total_frames = 0;
 };
diff --git a/Source/Core/InputCommon/ControlReference/ControlReference.cpp b/Source/Core/InputCommon/ControlReference/ControlReference.cpp
index 4bdfbddfef..795204cc05 100644
--- a/Source/Core/InputCommon/ControlReference/ControlReference.cpp
+++ b/Source/Core/InputCommon/ControlReference/ControlReference.cpp
@@ -58,9 +58,7 @@ std::optional<std::string> ControlReference::SetExpression(std::string expr)
   return parse_result.description;
 }
 
-ControlReference::ControlReference() : range(1), m_parsed_expression(nullptr)
-{
-}
+ControlReference::ControlReference() = default;
 
 ControlReference::~ControlReference() = default;
 
diff --git a/Source/Core/InputCommon/ControlReference/ControlReference.h b/Source/Core/InputCommon/ControlReference/ControlReference.h
index da6e10a5c2..f12e354bb3 100644
--- a/Source/Core/InputCommon/ControlReference/ControlReference.h
+++ b/Source/Core/InputCommon/ControlReference/ControlReference.h
@@ -41,13 +41,14 @@ public:
   // Returns a human-readable error description when the given expression is invalid.
   std::optional<std::string> SetExpression(std::string expr);
 
-  ControlState range;
+  ControlState range = 1;
 
 protected:
   ControlReference();
   std::string m_expression;
   std::unique_ptr<ciface::ExpressionParser::Expression> m_parsed_expression;
-  ciface::ExpressionParser::ParseStatus m_parse_status;
+  ciface::ExpressionParser::ParseStatus m_parse_status =
+      ciface::ExpressionParser::ParseStatus::EmptyExpression;
 };
 
 template <>
diff --git a/Source/Core/InputCommon/ControlReference/ExpressionParser.h b/Source/Core/InputCommon/ControlReference/ExpressionParser.h
index 16554738eb..405445b8a0 100644
--- a/Source/Core/InputCommon/ControlReference/ExpressionParser.h
+++ b/Source/Core/InputCommon/ControlReference/ExpressionParser.h
@@ -181,7 +181,7 @@ public:
   static ParseResult MakeSuccessfulResult(std::unique_ptr<Expression>&& expr);
   static ParseResult MakeErrorResult(Token token, std::string description);
 
-  ParseStatus status;
+  ParseStatus status = ParseStatus::EmptyExpression;
   std::unique_ptr<Expression> expr;
 
   // Used for parse errors:
diff --git a/Source/Core/InputCommon/ControllerInterface/CoreDevice.h b/Source/Core/InputCommon/ControllerInterface/CoreDevice.h
index def895afa1..2840f43463 100644
--- a/Source/Core/InputCommon/ControllerInterface/CoreDevice.h
+++ b/Source/Core/InputCommon/ControllerInterface/CoreDevice.h
@@ -174,7 +174,7 @@ protected:
   void AddCombinedInput(std::string name, const std::pair<std::string, std::string>& inputs);
 
 private:
-  int m_id;
+  int m_id = 0;
   std::vector<Input*> m_inputs;
   std::vector<Output*> m_outputs;
 };
@@ -216,10 +216,10 @@ public:
   struct InputDetection
   {
     std::shared_ptr<Device> device;
-    Device::Input* input;
+    Device::Input* input = nullptr;
     Clock::time_point press_time;
     std::optional<Clock::time_point> release_time;
-    ControlState smoothness;
+    ControlState smoothness = 0;
   };
 
   Device::Input* FindInput(std::string_view name, const Device* def_dev) const;
diff --git a/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.cpp b/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.cpp
index 5a6c6c221e..e7a8bea6fe 100644
--- a/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.cpp
@@ -177,9 +177,6 @@ Joystick::Joystick(const LPDIRECTINPUTDEVICE8 device) : m_device(device)
     InitForceFeedback(m_device, num_ff_axes);
   }
 
-  // Zero inputs:
-  m_state_in = {};
-
   // Set hats to center:
   // "The center position is normally reported as -1" -MSDN
   std::fill(std::begin(m_state_in.rgdwPOV), std::end(m_state_in.rgdwPOV), -1);
diff --git a/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.h b/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.h
index be04becf41..a142aeba00 100644
--- a/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.h
+++ b/Source/Core/InputCommon/ControllerInterface/DInput/DInputJoystick.h
@@ -70,7 +70,7 @@ public:
 private:
   const LPDIRECTINPUTDEVICE8 m_device;
 
-  DIJOYSTATE m_state_in;
+  DIJOYSTATE m_state_in{};
 
   bool m_buffered;
 };
diff --git a/Source/Core/InputCommon/ControllerInterface/DInput/DInputKeyboardMouse.h b/Source/Core/InputCommon/ControllerInterface/DInput/DInputKeyboardMouse.h
index d174f4a28e..eba4c8ab93 100644
--- a/Source/Core/InputCommon/ControllerInterface/DInput/DInputKeyboardMouse.h
+++ b/Source/Core/InputCommon/ControllerInterface/DInput/DInputKeyboardMouse.h
@@ -22,10 +22,10 @@ class KeyboardMouse : public Core::Device
 private:
   struct State
   {
-    BYTE keyboard[256];
+    BYTE keyboard[256]{};
 
     // Old smoothed relative mouse movement.
-    DIMOUSESTATE2 mouse;
+    DIMOUSESTATE2 mouse{};
 
     // Normalized mouse cursor position.
     Common::TVec2<ControlState> cursor;
diff --git a/Source/Core/InputCommon/ControllerInterface/DualShockUDPClient/DualShockUDPClient.cpp b/Source/Core/InputCommon/ControllerInterface/DualShockUDPClient/DualShockUDPClient.cpp
index b63a8582ae..7342ef4d47 100644
--- a/Source/Core/InputCommon/ControllerInterface/DualShockUDPClient/DualShockUDPClient.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/DualShockUDPClient/DualShockUDPClient.cpp
@@ -191,7 +191,7 @@ struct Server
   std::string m_description;
   std::string m_address;
   u16 m_port;
-  std::array<Proto::MessageType::PortInfo, Proto::PORT_COUNT> m_port_info;
+  std::array<Proto::MessageType::PortInfo, Proto::PORT_COUNT> m_port_info{};
   sf::UdpSocket m_socket;
   SteadyClock::time_point m_disconnect_time = SteadyClock::now();
 };
diff --git a/Source/Core/InputCommon/GCPadStatus.h b/Source/Core/InputCommon/GCPadStatus.h
index 62cd071f26..74849e5594 100644
--- a/Source/Core/InputCommon/GCPadStatus.h
+++ b/Source/Core/InputCommon/GCPadStatus.h
@@ -30,16 +30,16 @@ enum PadButton
 
 struct GCPadStatus
 {
-  u16 button;       // Or-ed PAD_BUTTON_* and PAD_TRIGGER_* bits
-  u8 stickX;        // 0 <= stickX       <= 255
-  u8 stickY;        // 0 <= stickY       <= 255
-  u8 substickX;     // 0 <= substickX    <= 255
-  u8 substickY;     // 0 <= substickY    <= 255
-  u8 triggerLeft;   // 0 <= triggerLeft  <= 255
-  u8 triggerRight;  // 0 <= triggerRight <= 255
-  u8 analogA;       // 0 <= analogA      <= 255
-  u8 analogB;       // 0 <= analogB      <= 255
-  bool isConnected{true};
+  u16 button = 0;       // Or-ed PAD_BUTTON_* and PAD_TRIGGER_* bits
+  u8 stickX = 0;        // 0 <= stickX       <= 255
+  u8 stickY = 0;        // 0 <= stickY       <= 255
+  u8 substickX = 0;     // 0 <= substickX    <= 255
+  u8 substickY = 0;     // 0 <= substickY    <= 255
+  u8 triggerLeft = 0;   // 0 <= triggerLeft  <= 255
+  u8 triggerRight = 0;  // 0 <= triggerRight <= 255
+  u8 analogA = 0;       // 0 <= analogA      <= 255
+  u8 analogB = 0;       // 0 <= analogB      <= 255
+  bool isConnected = true;
 
   static const u8 MAIN_STICK_CENTER_X = 0x80;
   static const u8 MAIN_STICK_CENTER_Y = 0x80;
diff --git a/Source/Core/UICommon/NetPlayIndex.h b/Source/Core/UICommon/NetPlayIndex.h
index 18bfa5c8e6..13fb674a66 100644
--- a/Source/Core/UICommon/NetPlayIndex.h
+++ b/Source/Core/UICommon/NetPlayIndex.h
@@ -23,11 +23,11 @@ struct NetPlaySession
   std::string game_id;
   std::string version;
 
-  int player_count;
-  int port;
+  int player_count = 0;
+  int port = 0;
 
-  bool has_password;
-  bool in_game;
+  bool has_password = false;
+  bool in_game = false;
 
   bool EncryptID(std::string_view password);
   std::optional<std::string> DecryptID(std::string_view password) const;
diff --git a/Source/Core/UpdaterCommon/UpdaterCommon.cpp b/Source/Core/UpdaterCommon/UpdaterCommon.cpp
index 74665bf4c1..f3c18c2609 100644
--- a/Source/Core/UpdaterCommon/UpdaterCommon.cpp
+++ b/Source/Core/UpdaterCommon/UpdaterCommon.cpp
@@ -49,7 +49,7 @@ struct TodoList
   struct DownloadOp
   {
     Manifest::Filename filename;
-    Manifest::Hash hash;
+    Manifest::Hash hash{};
   };
   std::vector<DownloadOp> to_download;
 
@@ -57,14 +57,14 @@ struct TodoList
   {
     Manifest::Filename filename;
     std::optional<Manifest::Hash> old_hash;
-    Manifest::Hash new_hash;
+    Manifest::Hash new_hash{};
   };
   std::vector<UpdateOp> to_update;
 
   struct DeleteOp
   {
     Manifest::Filename filename;
-    Manifest::Hash old_hash;
+    Manifest::Hash old_hash{};
   };
   std::vector<DeleteOp> to_delete;
 
diff --git a/Source/Core/VideoBackends/D3D/D3DPerfQuery.h b/Source/Core/VideoBackends/D3D/D3DPerfQuery.h
index a21c6a358b..fc1848f29a 100644
--- a/Source/Core/VideoBackends/D3D/D3DPerfQuery.h
+++ b/Source/Core/VideoBackends/D3D/D3DPerfQuery.h
@@ -26,7 +26,7 @@ private:
   struct ActiveQuery
   {
     ComPtr<ID3D11Query> query;
-    PerfQueryGroup query_type;
+    PerfQueryGroup query_type{};
   };
 
   void WeakFlush();
diff --git a/Source/Core/VideoBackends/D3D12/D3D12BoundingBox.h b/Source/Core/VideoBackends/D3D12/D3D12BoundingBox.h
index 03aa892b39..d2d95c5c83 100644
--- a/Source/Core/VideoBackends/D3D12/D3D12BoundingBox.h
+++ b/Source/Core/VideoBackends/D3D12/D3D12BoundingBox.h
@@ -34,7 +34,7 @@ private:
   ComPtr<ID3D12Resource> m_gpu_buffer;
   ComPtr<ID3D12Resource> m_readback_buffer;
   StreamBuffer m_upload_buffer;
-  DescriptorHandle m_gpu_descriptor;
+  DescriptorHandle m_gpu_descriptor{};
 };
 
 }  // namespace DX12
diff --git a/Source/Core/VideoBackends/D3D12/DescriptorHeapManager.h b/Source/Core/VideoBackends/D3D12/DescriptorHeapManager.h
index 6ab9a7f939..ce4d23b533 100644
--- a/Source/Core/VideoBackends/D3D12/DescriptorHeapManager.h
+++ b/Source/Core/VideoBackends/D3D12/DescriptorHeapManager.h
@@ -66,7 +66,7 @@ private:
   u32 m_descriptor_increment_size = 0;
   u32 m_current_offset = 0;
 
-  D3D12_CPU_DESCRIPTOR_HANDLE m_heap_base_cpu;
+  D3D12_CPU_DESCRIPTOR_HANDLE m_heap_base_cpu{};
 
   std::unordered_map<SamplerState::StorageType, D3D12_CPU_DESCRIPTOR_HANDLE> m_sampler_map;
 };
diff --git a/Source/Core/VideoBackends/OGL/ProgramShaderCache.h b/Source/Core/VideoBackends/OGL/ProgramShaderCache.h
index eb1f6d21d2..9e198987b8 100644
--- a/Source/Core/VideoBackends/OGL/ProgramShaderCache.h
+++ b/Source/Core/VideoBackends/OGL/ProgramShaderCache.h
@@ -59,7 +59,7 @@ struct PipelineProgramKeyHash
 
 struct PipelineProgram
 {
-  PipelineProgramKey key;
+  PipelineProgramKey key{};
   SHADER shader;
   std::atomic_size_t reference_count{1};
   bool binary_retrieved = false;
diff --git a/Source/Core/VideoBackends/Software/SWVertexLoader.h b/Source/Core/VideoBackends/Software/SWVertexLoader.h
index 5df794c822..4bc9f67ca8 100644
--- a/Source/Core/VideoBackends/Software/SWVertexLoader.h
+++ b/Source/Core/VideoBackends/Software/SWVertexLoader.h
@@ -25,6 +25,6 @@ protected:
   void SetFormat(u8 attributeIndex, u8 primitiveType);
   void ParseVertex(const PortableVertexDeclaration& vdec, int index);
 
-  InputVertexData m_vertex;
+  InputVertexData m_vertex{};
   SetupUnit m_setup_unit;
 };
diff --git a/Source/Core/VideoBackends/Software/SetupUnit.h b/Source/Core/VideoBackends/Software/SetupUnit.h
index 3bab4257e6..a9f9584e07 100644
--- a/Source/Core/VideoBackends/Software/SetupUnit.h
+++ b/Source/Core/VideoBackends/Software/SetupUnit.h
@@ -8,12 +8,12 @@
 
 class SetupUnit
 {
-  u8 m_PrimType;
-  int m_VertexCounter;
+  u8 m_PrimType = 0;
+  int m_VertexCounter = 0;
 
   OutputVertexData m_Vertices[3];
-  OutputVertexData* m_VertPointer[3];
-  OutputVertexData* m_VertWritePointer;
+  OutputVertexData* m_VertPointer[3]{};
+  OutputVertexData* m_VertWritePointer{};
 
   void SetupQuad();
   void SetupTriangle();
diff --git a/Source/Core/VideoBackends/Software/Vec3.h b/Source/Core/VideoBackends/Software/Vec3.h
index 7392ccdaa8..a7efd9c400 100644
--- a/Source/Core/VideoBackends/Software/Vec3.h
+++ b/Source/Core/VideoBackends/Software/Vec3.h
@@ -11,7 +11,7 @@ class Vec3
 public:
   float x, y, z;
 
-  Vec3() {}
+  Vec3() = default;
   explicit Vec3(float f) { x = y = z = f; }
   explicit Vec3(const float* f)
   {
diff --git a/Source/Core/VideoBackends/Vulkan/CommandBufferManager.h b/Source/Core/VideoBackends/Vulkan/CommandBufferManager.h
index 2f5477f5d0..632e43534a 100644
--- a/Source/Core/VideoBackends/Vulkan/CommandBufferManager.h
+++ b/Source/Core/VideoBackends/Vulkan/CommandBufferManager.h
@@ -120,7 +120,7 @@ private:
   u64 m_completed_fence_counter = 0;
 
   std::array<FrameResources, NUM_COMMAND_BUFFERS> m_frame_resources;
-  u32 m_current_frame;
+  u32 m_current_frame = 0;
 
   // Threaded command buffer execution
   // Semaphore determines when a command buffer can be queued
diff --git a/Source/Core/VideoBackends/Vulkan/VKSwapChain.h b/Source/Core/VideoBackends/Vulkan/VKSwapChain.h
index 52d3bc81bb..0077a93ec1 100644
--- a/Source/Core/VideoBackends/Vulkan/VKSwapChain.h
+++ b/Source/Core/VideoBackends/Vulkan/VKSwapChain.h
@@ -86,7 +86,7 @@ private:
 
   struct SwapChainImage
   {
-    VkImage image;
+    VkImage image{};
     std::unique_ptr<VKTexture> texture;
     std::unique_ptr<VKFramebuffer> framebuffer;
   };
diff --git a/Source/Core/VideoCommon/CPMemory.h b/Source/Core/VideoCommon/CPMemory.h
index 038e6787ea..81d0316cec 100644
--- a/Source/Core/VideoCommon/CPMemory.h
+++ b/Source/Core/VideoCommon/CPMemory.h
@@ -607,19 +607,19 @@ class VertexLoaderBase;
 // STATE_TO_SAVE
 struct CPState final
 {
-  u32 array_bases[CP_NUM_ARRAYS];
-  u32 array_strides[CP_NUM_ARRAYS];
-  TMatrixIndexA matrix_index_a;
-  TMatrixIndexB matrix_index_b;
+  u32 array_bases[CP_NUM_ARRAYS]{};
+  u32 array_strides[CP_NUM_ARRAYS]{};
+  TMatrixIndexA matrix_index_a{};
+  TMatrixIndexB matrix_index_b{};
   TVtxDesc vtx_desc;
   // Most games only use the first VtxAttr and simply reconfigure it all the time as needed.
-  VAT vtx_attr[CP_NUM_VAT_REG];
+  VAT vtx_attr[CP_NUM_VAT_REG]{};
 
   // Attributes that actually belong to VertexLoaderManager:
-  BitSet32 attr_dirty;
-  bool bases_dirty;
-  VertexLoaderBase* vertex_loaders[CP_NUM_VAT_REG];
-  int last_id;
+  BitSet32 attr_dirty{};
+  bool bases_dirty = false;
+  VertexLoaderBase* vertex_loaders[CP_NUM_VAT_REG]{};
+  int last_id = 0;
 };
 
 class PointerWrap;
diff --git a/Source/Core/VideoCommon/CommandProcessor.h b/Source/Core/VideoCommon/CommandProcessor.h
index e73fecfe41..66ef981cac 100644
--- a/Source/Core/VideoCommon/CommandProcessor.h
+++ b/Source/Core/VideoCommon/CommandProcessor.h
@@ -20,8 +20,8 @@ struct SCPFifoStruct
   // fifo registers
   std::atomic<u32> CPBase;
   std::atomic<u32> CPEnd;
-  u32 CPHiWatermark;
-  u32 CPLoWatermark;
+  u32 CPHiWatermark = 0;
+  u32 CPLoWatermark = 0;
   std::atomic<u32> CPReadWriteDistance;
   std::atomic<u32> CPWritePointer;
   std::atomic<u32> CPReadPointer;
diff --git a/Source/Core/VideoCommon/FrameDump.h b/Source/Core/VideoCommon/FrameDump.h
index 6024d9ec8e..23e3bead20 100644
--- a/Source/Core/VideoCommon/FrameDump.h
+++ b/Source/Core/VideoCommon/FrameDump.h
@@ -30,10 +30,10 @@ public:
 
   struct FrameData
   {
-    const u8* data;
-    int width;
-    int height;
-    int stride;
+    const u8* data = nullptr;
+    int width = 0;
+    int height = 0;
+    int stride = 0;
     FrameState state;
   };
 
diff --git a/Source/Core/VideoCommon/GXPipelineTypes.h b/Source/Core/VideoCommon/GXPipelineTypes.h
index 38193405c5..231bddefc1 100644
--- a/Source/Core/VideoCommon/GXPipelineTypes.h
+++ b/Source/Core/VideoCommon/GXPipelineTypes.h
@@ -35,10 +35,19 @@ struct GXPipelineUid
   // and this map lookup can happen every draw call. However, as using memcmp() will also compare
   // any padding bytes, we have to ensure these are zeroed out.
   GXPipelineUid() { std::memset(static_cast<void*>(this), 0, sizeof(*this)); }
+#ifdef _MSC_VER
+#pragma warning(push)
+// Disable warning for uninitialized member variables, as MSVC doesn't recognise that memcpy
+// performs this initialization.
+#pragma warning(disable : 26495)
+#endif
   GXPipelineUid(const GXPipelineUid& rhs)
   {
     std::memcpy(static_cast<void*>(this), &rhs, sizeof(*this));
   }
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
   GXPipelineUid& operator=(const GXPipelineUid& rhs)
   {
     std::memcpy(static_cast<void*>(this), &rhs, sizeof(*this));
@@ -65,10 +74,18 @@ struct GXUberPipelineUid
   BlendingState blending_state;
 
   GXUberPipelineUid() { std::memset(static_cast<void*>(this), 0, sizeof(*this)); }
+#ifdef _MSC_VER
+#pragma warning(push)
+// Disable warning for uninitialized member variables
+#pragma warning(disable : 26495)
+#endif
   GXUberPipelineUid(const GXUberPipelineUid& rhs)
   {
     std::memcpy(static_cast<void*>(this), &rhs, sizeof(*this));
   }
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
   GXUberPipelineUid& operator=(const GXUberPipelineUid& rhs)
   {
     std::memcpy(static_cast<void*>(this), &rhs, sizeof(*this));
@@ -90,23 +107,23 @@ struct GXUberPipelineUid
 #pragma pack(push, 1)
 struct SerializedGXPipelineUid
 {
-  PortableVertexDeclaration vertex_decl;
+  PortableVertexDeclaration vertex_decl{};
   VertexShaderUid vs_uid;
   GeometryShaderUid gs_uid;
   PixelShaderUid ps_uid;
-  u32 rasterization_state_bits;
-  u32 depth_state_bits;
-  u32 blending_state_bits;
+  u32 rasterization_state_bits = 0;
+  u32 depth_state_bits = 0;
+  u32 blending_state_bits = 0;
 };
 struct SerializedGXUberPipelineUid
 {
-  PortableVertexDeclaration vertex_decl;
+  PortableVertexDeclaration vertex_decl{};
   UberShader::VertexShaderUid vs_uid;
   GeometryShaderUid gs_uid;
   UberShader::PixelShaderUid ps_uid;
-  u32 rasterization_state_bits;
-  u32 depth_state_bits;
-  u32 blending_state_bits;
+  u32 rasterization_state_bits = 0;
+  u32 depth_state_bits = 0;
+  u32 blending_state_bits = 0;
 };
 #pragma pack(pop)
 
diff --git a/Source/Core/VideoCommon/HiresTextures.h b/Source/Core/VideoCommon/HiresTextures.h
index 64e20746f2..78e40460db 100644
--- a/Source/Core/VideoCommon/HiresTextures.h
+++ b/Source/Core/VideoCommon/HiresTextures.h
@@ -54,6 +54,6 @@ private:
   static bool LoadTexture(Level& level, const std::vector<u8>& buffer);
   static void Prefetch();
 
-  HiresTexture() {}
-  bool m_has_arbitrary_mipmaps;
+  HiresTexture() = default;
+  bool m_has_arbitrary_mipmaps = false;
 };
diff --git a/Source/Core/VideoCommon/PostProcessing.h b/Source/Core/VideoCommon/PostProcessing.h
index 55f92c5914..aafee8f1f6 100644
--- a/Source/Core/VideoCommon/PostProcessing.h
+++ b/Source/Core/VideoCommon/PostProcessing.h
@@ -31,7 +31,7 @@ public:
       OPTION_INTEGER,
     };
 
-    bool m_bool_value;
+    bool m_bool_value = false;
 
     std::vector<float> m_float_values;
     std::vector<s32> m_integer_values;
@@ -45,12 +45,12 @@ public:
     std::vector<float> m_float_step_values;
     std::vector<s32> m_integer_step_values;
 
-    OptionType m_type;
+    OptionType m_type = OptionType::OPTION_BOOL;
 
     std::string m_gui_name;
     std::string m_option_name;
     std::string m_dependent_option;
-    bool m_dirty;
+    bool m_dirty = false;
   };
 
   using ConfigMap = std::map<std::string, ConfigurationOption>;
diff --git a/Source/Core/VideoCommon/ShaderCache.h b/Source/Core/VideoCommon/ShaderCache.h
index b083927de4..c1b8f55b55 100644
--- a/Source/Core/VideoCommon/ShaderCache.h
+++ b/Source/Core/VideoCommon/ShaderCache.h
@@ -211,7 +211,7 @@ private:
     struct Shader
     {
       std::unique_ptr<AbstractShader> shader;
-      bool pending;
+      bool pending = false;
     };
     std::map<Uid, Shader> shader_map;
     LinearDiskCache<Uid, u8> disk_cache;
diff --git a/Source/Core/VideoCommon/TextureCacheBase.h b/Source/Core/VideoCommon/TextureCacheBase.h
index 12db848aa3..3fa9b85aa0 100644
--- a/Source/Core/VideoCommon/TextureCacheBase.h
+++ b/Source/Core/VideoCommon/TextureCacheBase.h
@@ -90,14 +90,14 @@ public:
     // common members
     std::unique_ptr<AbstractTexture> texture;
     std::unique_ptr<AbstractFramebuffer> framebuffer;
-    u32 addr;
-    u32 size_in_bytes;
-    u64 base_hash;
-    u64 hash;  // for paletted textures, hash = base_hash ^ palette_hash
+    u32 addr = 0;
+    u32 size_in_bytes = 0;
+    u64 base_hash = 0;
+    u64 hash = 0;  // for paletted textures, hash = base_hash ^ palette_hash
     TextureAndTLUTFormat format;
-    u32 memory_stride;
-    bool is_efb_copy;
-    bool is_custom_tex;
+    u32 memory_stride = 0;
+    bool is_efb_copy = false;
+    bool is_custom_tex = false;
     bool may_have_overlapping_textures = true;
     bool tmem_only = false;           // indicates that this texture only exists in the tmem cache
     bool has_arbitrary_mips = false;  // indicates that the mips in this texture are arbitrary
@@ -105,13 +105,14 @@ public:
     bool should_force_safe_hashing = false;  // for XFB
     bool is_xfb_copy = false;
     bool is_xfb_container = false;
-    u64 id;
+    u64 id = 0;
 
     bool reference_changed = false;  // used by xfb to determine when a reference xfb changed
 
-    unsigned int native_width,
-        native_height;  // Texture dimensions from the GameCube's point of view
-    unsigned int native_levels;
+    // Texture dimensions from the GameCube's point of view
+    u32 native_width = 0;
+    u32 native_height = 0;
+    u32 native_levels = 0;
 
     // used to delete textures which haven't been used for TEXTURE_KILL_THRESHOLD frames
     int frameCount = FRAMECOUNT_INVALID;
diff --git a/Source/Core/VideoCommon/VertexLoaderBase.h b/Source/Core/VideoCommon/VertexLoaderBase.h
index 77e3d85aa7..26ec5c6026 100644
--- a/Source/Core/VideoCommon/VertexLoaderBase.h
+++ b/Source/Core/VideoCommon/VertexLoaderBase.h
@@ -16,8 +16,8 @@ class DataReader;
 
 class VertexLoaderUID
 {
-  std::array<u32, 5> vid;
-  size_t hash;
+  std::array<u32, 5> vid{};
+  size_t hash = 0;
 
 public:
   VertexLoaderUID() {}
diff --git a/Source/Core/VideoCommon/VideoConfig.cpp b/Source/Core/VideoCommon/VideoConfig.cpp
index 70ad7096e9..255e1722b9 100644
--- a/Source/Core/VideoCommon/VideoConfig.cpp
+++ b/Source/Core/VideoCommon/VideoConfig.cpp
@@ -33,29 +33,6 @@ void UpdateActiveConfig()
   g_ActiveConfig.bVSyncActive = IsVSyncActive(g_ActiveConfig.bVSync);
 }
 
-VideoConfig::VideoConfig()
-{
-  // Needed for the first frame, I think
-  fAspectRatioHackW = 1;
-  fAspectRatioHackH = 1;
-
-  // disable all features by default
-  backend_info.api_type = APIType::Nothing;
-  backend_info.MaxTextureSize = 16384;
-  backend_info.bSupportsExclusiveFullscreen = false;
-  backend_info.bSupportsMultithreading = false;
-  backend_info.bSupportsST3CTextures = false;
-  backend_info.bSupportsBPTCTextures = false;
-
-  bEnableValidationLayer = false;
-
-#if defined(ANDROID)
-  bBackendMultithreading = false;
-#else
-  bBackendMultithreading = true;
-#endif
-}
-
 void VideoConfig::Refresh()
 {
   if (!s_has_registered_callback)
diff --git a/Source/Core/VideoCommon/VideoConfig.h b/Source/Core/VideoCommon/VideoConfig.h
index cb5e03be2b..495eef6c28 100644
--- a/Source/Core/VideoCommon/VideoConfig.h
+++ b/Source/Core/VideoCommon/VideoConfig.h
@@ -13,8 +13,7 @@
 #include <vector>
 
 #include "Common/CommonTypes.h"
-
-enum class APIType;
+#include "VideoCommon/VideoCommon.h"
 
 // Log in two categories, and save three other options in the same byte
 #define CONF_LOG 1
@@ -53,135 +52,140 @@ enum class ShaderCompilationMode : int
 // NEVER inherit from this class.
 struct VideoConfig final
 {
-  VideoConfig();
+  VideoConfig() = default;
   void Refresh();
   void VerifyValidity();
 
   // General
-  bool bVSync;
-  bool bVSyncActive;
-  bool bWidescreenHack;
-  AspectMode aspect_mode;
-  AspectMode suggested_aspect_mode;
-  bool bCrop;  // Aspect ratio controls.
-  bool bShaderCache;
+  bool bVSync = false;
+  bool bVSyncActive = false;
+  bool bWidescreenHack = false;
+  AspectMode aspect_mode{};
+  AspectMode suggested_aspect_mode{};
+  bool bCrop = false;  // Aspect ratio controls.
+  bool bShaderCache = false;
 
   // Enhancements
-  u32 iMultisamples;
-  bool bSSAA;
-  int iEFBScale;
-  bool bForceFiltering;
-  int iMaxAnisotropy;
+  u32 iMultisamples = 0;
+  bool bSSAA = false;
+  int iEFBScale = 0;
+  bool bForceFiltering = false;
+  int iMaxAnisotropy = 0;
   std::string sPostProcessingShader;
-  bool bForceTrueColor;
-  bool bDisableCopyFilter;
-  bool bArbitraryMipmapDetection;
-  float fArbitraryMipmapDetectionThreshold;
+  bool bForceTrueColor = false;
+  bool bDisableCopyFilter = false;
+  bool bArbitraryMipmapDetection = false;
+  float fArbitraryMipmapDetectionThreshold = 0;
 
   // Information
-  bool bShowFPS;
-  bool bShowNetPlayPing;
-  bool bShowNetPlayMessages;
-  bool bOverlayStats;
-  bool bOverlayProjStats;
-  bool bTexFmtOverlayEnable;
-  bool bTexFmtOverlayCenter;
-  bool bLogRenderTimeToFile;
+  bool bShowFPS = false;
+  bool bShowNetPlayPing = false;
+  bool bShowNetPlayMessages = false;
+  bool bOverlayStats = false;
+  bool bOverlayProjStats = false;
+  bool bTexFmtOverlayEnable = false;
+  bool bTexFmtOverlayCenter = false;
+  bool bLogRenderTimeToFile = false;
 
   // Render
-  bool bWireFrame;
-  bool bDisableFog;
+  bool bWireFrame = false;
+  bool bDisableFog = false;
 
   // Utility
-  bool bDumpTextures;
-  bool bDumpMipmapTextures;
-  bool bDumpBaseTextures;
-  bool bHiresTextures;
-  bool bCacheHiresTextures;
-  bool bDumpEFBTarget;
-  bool bDumpXFBTarget;
-  bool bDumpFramesAsImages;
-  bool bUseFFV1;
+  bool bDumpTextures = false;
+  bool bDumpMipmapTextures = false;
+  bool bDumpBaseTextures = false;
+  bool bHiresTextures = false;
+  bool bCacheHiresTextures = false;
+  bool bDumpEFBTarget = false;
+  bool bDumpXFBTarget = false;
+  bool bDumpFramesAsImages = false;
+  bool bUseFFV1 = false;
   std::string sDumpCodec;
   std::string sDumpEncoder;
   std::string sDumpFormat;
   std::string sDumpPath;
-  bool bInternalResolutionFrameDumps;
-  bool bBorderlessFullscreen;
-  bool bEnableGPUTextureDecoding;
-  int iBitrateKbps;
+  bool bInternalResolutionFrameDumps = false;
+  bool bBorderlessFullscreen = false;
+  bool bEnableGPUTextureDecoding = false;
+  int iBitrateKbps = 0;
 
   // Hacks
-  bool bEFBAccessEnable;
-  bool bEFBAccessDeferInvalidation;
-  bool bPerfQueriesEnable;
-  bool bBBoxEnable;
-  bool bForceProgressive;
+  bool bEFBAccessEnable = false;
+  bool bEFBAccessDeferInvalidation = false;
+  bool bPerfQueriesEnable = false;
+  bool bBBoxEnable = false;
+  bool bForceProgressive = false;
 
-  bool bEFBEmulateFormatChanges;
-  bool bSkipEFBCopyToRam;
-  bool bSkipXFBCopyToRam;
-  bool bDisableCopyToVRAM;
-  bool bDeferEFBCopies;
-  bool bImmediateXFB;
-  bool bSkipPresentingDuplicateXFBs;
-  bool bCopyEFBScaled;
-  int iSafeTextureCache_ColorSamples;
-  float fAspectRatioHackW, fAspectRatioHackH;
-  bool bEnablePixelLighting;
-  bool bFastDepthCalc;
-  bool bVertexRounding;
-  int iEFBAccessTileSize;
-  int iLog;           // CONF_ bits
-  int iSaveTargetId;  // TODO: Should be dropped
-  u32 iMissingColorValue;
+  bool bEFBEmulateFormatChanges = false;
+  bool bSkipEFBCopyToRam = false;
+  bool bSkipXFBCopyToRam = false;
+  bool bDisableCopyToVRAM = false;
+  bool bDeferEFBCopies = false;
+  bool bImmediateXFB = false;
+  bool bSkipPresentingDuplicateXFBs = false;
+  bool bCopyEFBScaled = false;
+  int iSafeTextureCache_ColorSamples = 0;
+  float fAspectRatioHackW = 1;  // Initial value needed for the first frame
+  float fAspectRatioHackH = 1;
+  bool bEnablePixelLighting = false;
+  bool bFastDepthCalc = false;
+  bool bVertexRounding = false;
+  int iEFBAccessTileSize = 0;
+  int iLog = 0;           // CONF_ bits
+  int iSaveTargetId = 0;  // TODO: Should be dropped
+  u32 iMissingColorValue = 0;
 
   // Stereoscopy
-  StereoMode stereo_mode;
-  int iStereoDepth;
-  int iStereoConvergence;
-  int iStereoConvergencePercentage;
-  bool bStereoSwapEyes;
-  bool bStereoEFBMonoDepth;
-  int iStereoDepthPercentage;
+  StereoMode stereo_mode{};
+  int iStereoDepth = 0;
+  int iStereoConvergence = 0;
+  int iStereoConvergencePercentage = 0;
+  bool bStereoSwapEyes = false;
+  bool bStereoEFBMonoDepth = false;
+  int iStereoDepthPercentage = 0;
 
   // D3D only config, mostly to be merged into the above
-  int iAdapter;
+  int iAdapter = 0;
 
   // VideoSW Debugging
-  int drawStart;
-  int drawEnd;
-  bool bZComploc;
-  bool bZFreeze;
-  bool bDumpObjects;
-  bool bDumpTevStages;
-  bool bDumpTevTextureFetches;
+  int drawStart = 0;
+  int drawEnd = 0;
+  bool bZComploc = false;
+  bool bZFreeze = false;
+  bool bDumpObjects = false;
+  bool bDumpTevStages = false;
+  bool bDumpTevTextureFetches = false;
 
   // Enable API validation layers, currently only supported with Vulkan.
-  bool bEnableValidationLayer;
+  bool bEnableValidationLayer = false;
 
   // Multithreaded submission, currently only supported with Vulkan.
-  bool bBackendMultithreading;
+#if defined(ANDROID)
+  bool bBackendMultithreading = false;
+#else
+  bool bBackendMultithreading = true;
+#endif
 
   // Early command buffer execution interval in number of draws.
   // Currently only supported with Vulkan.
-  int iCommandBufferExecuteInterval;
+  int iCommandBufferExecuteInterval = 0;
 
   // Shader compilation settings.
-  bool bWaitForShadersBeforeStarting;
-  ShaderCompilationMode iShaderCompilationMode;
+  bool bWaitForShadersBeforeStarting = false;
+  ShaderCompilationMode iShaderCompilationMode{};
 
   // Number of shader compiler threads.
   // 0 disables background compilation.
   // -1 uses an automatic number based on the CPU threads.
-  int iShaderCompilerThreads;
-  int iShaderPrecompilerThreads;
+  int iShaderCompilerThreads = 0;
+  int iShaderPrecompilerThreads = 0;
 
   // Static config per API
   // TODO: Move this out of VideoConfig
   struct
   {
-    APIType api_type;
+    APIType api_type = APIType::Nothing;
 
     std::vector<std::string> Adapters;  // for D3D
     std::vector<u32> AAModes;
@@ -189,42 +193,43 @@ struct VideoConfig final
     // TODO: merge AdapterName and Adapters array
     std::string AdapterName;  // for OpenGL
 
-    u32 MaxTextureSize;
-    bool bUsesLowerLeftOrigin;
+    u32 MaxTextureSize = 16384;
+    bool bUsesLowerLeftOrigin = false;
 
-    bool bSupportsExclusiveFullscreen;
-    bool bSupportsDualSourceBlend;
-    bool bSupportsPrimitiveRestart;
-    bool bSupportsOversizedViewports;
-    bool bSupportsGeometryShaders;
-    bool bSupportsComputeShaders;
-    bool bSupports3DVision;
-    bool bSupportsEarlyZ;         // needed by PixelShaderGen, so must stay in VideoCommon
-    bool bSupportsBindingLayout;  // Needed by ShaderGen, so must stay in VideoCommon
-    bool bSupportsBBox;
-    bool bSupportsGSInstancing;  // Needed by GeometryShaderGen, so must stay in VideoCommon
-    bool bSupportsPostProcessing;
-    bool bSupportsPaletteConversion;
-    bool bSupportsClipControl;  // Needed by VertexShaderGen, so must stay in VideoCommon
-    bool bSupportsSSAA;
-    bool bSupportsFragmentStoresAndAtomics;  // a.k.a. OpenGL SSBOs a.k.a. Direct3D UAVs
-    bool bSupportsDepthClamp;  // Needed by VertexShaderGen, so must stay in VideoCommon
-    bool bSupportsReversedDepthRange;
-    bool bSupportsLogicOp;
-    bool bSupportsMultithreading;
-    bool bSupportsGPUTextureDecoding;
-    bool bSupportsST3CTextures;
-    bool bSupportsCopyToVram;
-    bool bSupportsBitfield;                // Needed by UberShaders, so must stay in VideoCommon
-    bool bSupportsDynamicSamplerIndexing;  // Needed by UberShaders, so must stay in VideoCommon
-    bool bSupportsBPTCTextures;
-    bool bSupportsFramebufferFetch;  // Used as an alternative to dual-source blend on GLES
-    bool bSupportsBackgroundCompiling;
-    bool bSupportsLargePoints;
-    bool bSupportsPartialDepthCopies;
-    bool bSupportsDepthReadback;
-    bool bSupportsShaderBinaries;
-    bool bSupportsPipelineCacheData;
+    bool bSupportsExclusiveFullscreen = false;
+    bool bSupportsDualSourceBlend = false;
+    bool bSupportsPrimitiveRestart = false;
+    bool bSupportsOversizedViewports = false;
+    bool bSupportsGeometryShaders = false;
+    bool bSupportsComputeShaders = false;
+    bool bSupports3DVision = false;
+    bool bSupportsEarlyZ = false;         // needed by PixelShaderGen, so must stay in VideoCommon
+    bool bSupportsBindingLayout = false;  // Needed by ShaderGen, so must stay in VideoCommon
+    bool bSupportsBBox = false;
+    bool bSupportsGSInstancing = false;  // Needed by GeometryShaderGen, so must stay in VideoCommon
+    bool bSupportsPostProcessing = false;
+    bool bSupportsPaletteConversion = false;
+    bool bSupportsClipControl = false;  // Needed by VertexShaderGen, so must stay in VideoCommon
+    bool bSupportsSSAA = false;
+    bool bSupportsFragmentStoresAndAtomics = false;  // a.k.a. OpenGL SSBOs a.k.a. Direct3D UAVs
+    bool bSupportsDepthClamp = false;  // Needed by VertexShaderGen, so must stay in VideoCommon
+    bool bSupportsReversedDepthRange = false;
+    bool bSupportsLogicOp = false;
+    bool bSupportsMultithreading = false;
+    bool bSupportsGPUTextureDecoding = false;
+    bool bSupportsST3CTextures = false;
+    bool bSupportsCopyToVram = false;
+    bool bSupportsBitfield = false;  // Needed by UberShaders, so must stay in VideoCommon
+    // Needed by UberShaders, so must stay in VideoCommon
+    bool bSupportsDynamicSamplerIndexing = false;
+    bool bSupportsBPTCTextures = false;
+    bool bSupportsFramebufferFetch = false;  // Used as an alternative to dual-source blend on GLES
+    bool bSupportsBackgroundCompiling = false;
+    bool bSupportsLargePoints = false;
+    bool bSupportsPartialDepthCopies = false;
+    bool bSupportsDepthReadback = false;
+    bool bSupportsShaderBinaries = false;
+    bool bSupportsPipelineCacheData = false;
   } backend_info;
 
   // Utility
diff --git a/Source/UnitTests/Common/x64EmitterTest.cpp b/Source/UnitTests/Common/x64EmitterTest.cpp
index 5817c912fe..dbbc6c26b4 100644
--- a/Source/UnitTests/Common/x64EmitterTest.cpp
+++ b/Source/UnitTests/Common/x64EmitterTest.cpp
@@ -163,8 +163,8 @@ protected:
 
   std::unique_ptr<X64CodeBlock> emitter;
   std::unique_ptr<disassembler> disasm;
-  u8* code_buffer;
-  u8* code_buffer_end;
+  u8* code_buffer = nullptr;
+  u8* code_buffer_end = nullptr;
 };
 
 #define TEST_INSTR_NO_OPERANDS(Name, ExpectedDisasm)                                               \
diff --git a/Source/UnitTests/Core/MMIOTest.cpp b/Source/UnitTests/Core/MMIOTest.cpp
index 8ad127c65f..9bcd2af135 100644
--- a/Source/UnitTests/Core/MMIOTest.cpp
+++ b/Source/UnitTests/Core/MMIOTest.cpp
@@ -67,7 +67,7 @@ class MappingTest : public testing::Test
 protected:
   virtual void SetUp() override { m_mapping = new MMIO::Mapping(); }
   virtual void TearDown() override { delete m_mapping; }
-  MMIO::Mapping* m_mapping;
+  MMIO::Mapping* m_mapping = nullptr;
 };
 
 TEST_F(MappingTest, ReadConstant)
diff --git a/Source/UnitTests/Core/PageFaultTest.cpp b/Source/UnitTests/Core/PageFaultTest.cpp
index 0ff9c46a61..841ba54609 100644
--- a/Source/UnitTests/Core/PageFaultTest.cpp
+++ b/Source/UnitTests/Core/PageFaultTest.cpp
@@ -43,7 +43,7 @@ public:
     return true;
   }
 
-  void* m_data;
+  void* m_data = nullptr;
   std::chrono::time_point<std::chrono::high_resolution_clock> m_pre_unprotect_time,
       m_post_unprotect_time;
 };