diff --git a/Source/Core/DiscIO/CMakeLists.txt b/Source/Core/DiscIO/CMakeLists.txt
index 604d9e8914..b3db39ce63 100644
--- a/Source/Core/DiscIO/CMakeLists.txt
+++ b/Source/Core/DiscIO/CMakeLists.txt
@@ -63,6 +63,7 @@ PUBLIC
   zstd
 
 PRIVATE
+  fmt::fmt
   minizip
   pugixml
   ZLIB::ZLIB
diff --git a/Source/Core/DiscIO/CompressedBlob.cpp b/Source/Core/DiscIO/CompressedBlob.cpp
index 4486b54827..58ce4ce912 100644
--- a/Source/Core/DiscIO/CompressedBlob.cpp
+++ b/Source/Core/DiscIO/CompressedBlob.cpp
@@ -15,6 +15,8 @@
 #include <string>
 #include <utility>
 #include <vector>
+
+#include <fmt/format.h>
 #include <zlib.h>
 
 #include "Common/Assert.h"
@@ -24,7 +26,6 @@
 #include "Common/Hash.h"
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
-#include "Common/StringUtil.h"
 #include "DiscIO/Blob.h"
 #include "DiscIO/CompressedBlob.h"
 #include "DiscIO/DiscScrubber.h"
@@ -256,8 +257,8 @@ static ConversionResultCode Output(OutputParameters parameters, File::IOFile* ou
         parameters.inpos == 0 ? 0 : static_cast<int>(100 * *position / parameters.inpos);
 
     const std::string text =
-        StringFromFormat(Common::GetStringT("%i of %i blocks. Compression ratio %i%%").c_str(),
-                         parameters.block_number, num_blocks, ratio);
+        fmt::format(Common::GetStringT("{0} of {1} blocks. Compression ratio {2}%"),
+                    parameters.block_number, num_blocks, ratio);
 
     const float completion = static_cast<float>(parameters.block_number) / num_blocks;
 
diff --git a/Source/Core/DiscIO/DiscExtractor.cpp b/Source/Core/DiscIO/DiscExtractor.cpp
index b12b56b5c2..c9b01759a1 100644
--- a/Source/Core/DiscIO/DiscExtractor.cpp
+++ b/Source/Core/DiscIO/DiscExtractor.cpp
@@ -9,10 +9,11 @@
 #include <locale>
 #include <optional>
 
+#include <fmt/format.h>
+
 #include "Common/CommonTypes.h"
 #include "Common/File.h"
 #include "Common/FileUtil.h"
-#include "Common/StringUtil.h"
 #include "DiscIO/Enums.h"
 #include "DiscIO/Filesystem.h"
 #include "DiscIO/Volume.h"
@@ -45,7 +46,7 @@ std::string NameForPartitionType(u32 partition_type, bool include_prefix)
       return include_prefix ? "P-" + type_as_game_id : type_as_game_id;
     }
 
-    return StringFromFormat(include_prefix ? "P%u" : "%u", partition_type);
+    return fmt::format(include_prefix ? "P{}" : "{}", partition_type);
   }
 }
 
diff --git a/Source/Core/DiscIO/NANDImporter.cpp b/Source/Core/DiscIO/NANDImporter.cpp
index 9c161bcc02..beb84e8357 100644
--- a/Source/Core/DiscIO/NANDImporter.cpp
+++ b/Source/Core/DiscIO/NANDImporter.cpp
@@ -9,12 +9,13 @@
 #include <cinttypes>
 #include <cstring>
 
+#include <fmt/format.h>
+
 #include "Common/Crypto/AES.h"
 #include "Common/File.h"
 #include "Common/FileUtil.h"
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
-#include "Common/StringUtil.h"
 #include "Common/Swap.h"
 #include "Core/IOS/ES/Formats.h"
 
@@ -132,9 +133,10 @@ std::string NANDImporter::GetPath(const NANDFSTEntry& entry, const std::string&
 
 std::string NANDImporter::FormatDebugString(const NANDFSTEntry& entry)
 {
-  return StringFromFormat("%12.12s 0x%02x 0x%02x 0x%04x 0x%04x 0x%08x 0x%04x 0x%04x 0x%04x 0x%08x",
-                          entry.name, entry.mode, entry.attr, entry.sub, entry.sib, entry.size,
-                          entry.x1, entry.uid, entry.gid, entry.x3);
+  return fmt::format(
+      "{:12.12} {:#04x} {:#04x} {:#06x} {:#06x} {:#010x} {:#06x} {:#06x} {:#06x} {:#010x}",
+      entry.name, entry.mode, entry.attr, entry.sub, entry.sib, entry.size, entry.x1, entry.uid,
+      entry.gid, entry.x3);
 }
 
 void NANDImporter::ProcessEntry(u16 entry_number, const std::string& parent_path)
@@ -216,7 +218,7 @@ bool NANDImporter::ExtractCertificates(const std::string& nand_root)
     return false;
   }
 
-  File::IOFile content_file(content_dir + StringFromFormat("%08x.app", content_metadata.id), "rb");
+  File::IOFile content_file(content_dir + fmt::format("{:08x}.app", content_metadata.id), "rb");
   std::vector<u8> content_bytes(content_file.GetSize());
   if (!content_file.ReadBytes(content_bytes.data(), content_bytes.size()))
   {
diff --git a/Source/Core/DiscIO/VolumeVerifier.cpp b/Source/Core/DiscIO/VolumeVerifier.cpp
index 6dee5b8796..e28159050b 100644
--- a/Source/Core/DiscIO/VolumeVerifier.cpp
+++ b/Source/Core/DiscIO/VolumeVerifier.cpp
@@ -16,6 +16,7 @@
 #include <string_view>
 #include <unordered_set>
 
+#include <fmt/format.h>
 #include <mbedtls/md5.h>
 #include <mbedtls/sha1.h>
 #include <pugixml.hpp>
@@ -519,10 +520,8 @@ bool VolumeVerifier::CheckPartition(const Partition& partition)
   if (partition.offset % VolumeWii::BLOCK_TOTAL_SIZE != 0 ||
       m_volume.PartitionOffsetToRawOffset(0, partition) % VolumeWii::BLOCK_TOTAL_SIZE != 0)
   {
-    AddProblem(
-        Severity::Medium,
-        StringFromFormat(Common::GetStringT("The %s partition is not properly aligned.").c_str(),
-                         name.c_str()));
+    AddProblem(Severity::Medium,
+               fmt::format(Common::GetStringT("The {0} partition is not properly aligned."), name));
   }
 
   if (!m_is_datel)
@@ -542,16 +541,14 @@ bool VolumeVerifier::CheckPartition(const Partition& partition)
     {
       AddProblem(
           Severity::Low,
-          StringFromFormat(Common::GetStringT("The %s partition is not correctly signed.").c_str(),
-                           name.c_str()));
+          fmt::format(Common::GetStringT("The {0} partition is not correctly signed."), name));
     }
   }
 
   if (m_volume.SupportsIntegrityCheck() && !m_volume.CheckH3TableIntegrity(partition))
   {
-    std::string text = StringFromFormat(
-        Common::GetStringT("The H3 hash table for the %s partition is not correct.").c_str(),
-        name.c_str());
+    std::string text = fmt::format(
+        Common::GetStringT("The H3 hash table for the {0} partition is not correct."), name);
     AddProblem(Severity::Low, std::move(text));
   }
 
@@ -584,9 +581,8 @@ bool VolumeVerifier::CheckPartition(const Partition& partition)
     // This can happen when certain programs that create WBFS files scrub the entirety of
     // the Masterpiece partitions in Super Smash Bros. Brawl without removing them from
     // the partition table. https://bugs.dolphin-emu.org/issues/8733
-    std::string text = StringFromFormat(
-        Common::GetStringT("The %s partition does not seem to contain valid data.").c_str(),
-        name.c_str());
+    std::string text = fmt::format(
+        Common::GetStringT("The {0} partition does not seem to contain valid data."), name);
     AddProblem(severity, std::move(text));
     return false;
   }
@@ -614,9 +610,8 @@ bool VolumeVerifier::CheckPartition(const Partition& partition)
       return true;
     }
 
-    std::string text = StringFromFormat(
-        Common::GetStringT("The %s partition does not have a valid file system.").c_str(),
-        name.c_str());
+    std::string text = fmt::format(
+        Common::GetStringT("The {0} partition does not have a valid file system."), name);
     AddProblem(severity, std::move(text));
     return false;
   }
@@ -675,7 +670,7 @@ std::string VolumeVerifier::GetPartitionName(std::optional<u32> type) const
     // (French), Clásicos (Spanish), Capolavori (Italian), 클래식 게임 체험판 (Korean).
     // If your language is not one of the languages above, consider leaving the string untranslated
     // so that people will recognize it as the name of the game mode.
-    name = StringFromFormat(Common::GetStringT("%s (Masterpiece)").c_str(), name.c_str());
+    name = fmt::format(Common::GetStringT("{0} (Masterpiece)"), name);
   }
   return name;
 }
@@ -903,10 +898,9 @@ void VolumeVerifier::CheckMisc()
         // Hacked version of the Wii Backup Disc (aka "pinkfish" disc).
         std::string proper_game_id = game_id_unencrypted;
         proper_game_id[0] = '4';
-        AddProblem(
-            Severity::Low,
-            StringFromFormat(Common::GetStringT("The game ID is %s but should be %s.").c_str(),
-                             game_id_unencrypted.c_str(), proper_game_id.c_str()));
+        AddProblem(Severity::Low,
+                   fmt::format(Common::GetStringT("The game ID is {0} but should be {1}."),
+                               game_id_unencrypted, proper_game_id));
         inconsistent_game_id = false;
       }
     }
@@ -1000,9 +994,9 @@ void VolumeVerifier::CheckMisc()
       {
         // Many fakesigned WADs have the common key index set to a (random?) bogus value.
         // For WADs, Dolphin will detect this and use the correct key, making this low severity.
-        std::string text = StringFromFormat(
+        std::string text = fmt::format(
             // i18n: This is "common" as in "shared", not the opposite of "uncommon"
-            Common::GetStringT("The specified common key index is %u but should be %u.").c_str(),
+            Common::GetStringT("The specified common key index is {0} but should be {1}."),
             specified_common_key_index, fixed_common_key_index);
         AddProblem(Severity::Low, std::move(text));
       }
@@ -1214,9 +1208,8 @@ void VolumeVerifier::Process()
     m_content_future = std::async(std::launch::async, [this, read_succeeded, content] {
       if (!read_succeeded || !m_volume.CheckContentIntegrity(content, m_data, m_ticket))
       {
-        AddProblem(
-            Severity::High,
-            StringFromFormat(Common::GetStringT("Content %08x is corrupt.").c_str(), content.id));
+        AddProblem(Severity::High,
+                   fmt::format(Common::GetStringT("Content {0:08x} is corrupt."), content.id));
       }
     });
 
@@ -1331,9 +1324,9 @@ void VolumeVerifier::Finish()
     if (blocks > 0)
     {
       const std::string name = GetPartitionName(m_volume.GetPartitionType(partition));
-      std::string text = StringFromFormat(
-          Common::GetStringT("Errors were found in %zu blocks in the %s partition.").c_str(),
-          blocks, name.c_str());
+      std::string text =
+          fmt::format(Common::GetStringT("Errors were found in {0} blocks in the {1} partition."),
+                      blocks, name);
       AddProblem(Severity::Medium, std::move(text));
     }
   }
@@ -1343,9 +1336,9 @@ void VolumeVerifier::Finish()
     if (blocks > 0)
     {
       const std::string name = GetPartitionName(m_volume.GetPartitionType(partition));
-      std::string text = StringFromFormat(
-          Common::GetStringT("Errors were found in %zu unused blocks in the %s partition.").c_str(),
-          blocks, name.c_str());
+      std::string text = fmt::format(
+          Common::GetStringT("Errors were found in {0} unused blocks in the {1} partition."),
+          blocks, name);
       AddProblem(Severity::Low, std::move(text));
     }
   }
diff --git a/Source/Core/DiscIO/WIABlob.cpp b/Source/Core/DiscIO/WIABlob.cpp
index 999d3136ac..75a058877a 100644
--- a/Source/Core/DiscIO/WIABlob.cpp
+++ b/Source/Core/DiscIO/WIABlob.cpp
@@ -16,6 +16,7 @@
 #include <type_traits>
 #include <utility>
 
+#include <fmt/format.h>
 #include <mbedtls/sha1.h>
 #include <zstd.h>
 
@@ -27,7 +28,6 @@
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
 #include "Common/ScopeGuard.h"
-#include "Common/StringUtil.h"
 #include "Common/Swap.h"
 
 #include "DiscIO/Blob.h"
@@ -617,9 +617,9 @@ std::string WIARVZFileReader<RVZ>::VersionToString(u32 version)
   const u8 d = version & 0xff;
 
   if (d == 0 || d == 0xff)
-    return StringFromFormat("%u.%02x.%02x", a, b, c);
+    return fmt::format("{}.{:02x}.{:02x}", a, b, c);
   else
-    return StringFromFormat("%u.%02x.%02x.beta%u", a, b, c, d);
+    return fmt::format("{}.{:02x}.{:02x}.beta{}", a, b, c, d);
 }
 
 template <bool RVZ>
@@ -1695,8 +1695,8 @@ ConversionResultCode WIARVZFileReader<RVZ>::RunCallback(size_t groups_written, u
     ratio = static_cast<int>(100 * bytes_written / bytes_read);
 
   const std::string text =
-      StringFromFormat(Common::GetStringT("%i of %i blocks. Compression ratio %i%%").c_str(),
-                       groups_written, total_groups, ratio);
+      fmt::format(Common::GetStringT("{0} of {1} blocks. Compression ratio {2}%"), groups_written,
+                  total_groups, ratio);
 
   const float completion = static_cast<float>(bytes_read) / iso_size;