diff --git a/.gdbinit b/.gdbinit
index 872fae6b0..f54495075 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -1,2 +1,4 @@
 # Ignore HighResolutionTimer custom event
 handle SIG34 nostop noprint
+# Ignore PosixTimer custom event
+handle SIG35 nostop noprint
diff --git a/src/xenia/base/testing/threading_test.cc b/src/xenia/base/testing/threading_test.cc
index f35d647dd..9e4187165 100644
--- a/src/xenia/base/testing/threading_test.cc
+++ b/src/xenia/base/testing/threading_test.cc
@@ -552,8 +552,112 @@ TEST_CASE("Wait on Multiple Mutants", "Mutant") {
   thread2.join();
 }
 
-TEST_CASE("Create and Trigger Timer", "Timer") {
-  // TODO(bwrsandman):
+TEST_CASE("Wait on Timer", "Timer") {
+  WaitResult result;
+  std::unique_ptr<Timer> timer;
+
+  // Test Manual Reset
+  timer = Timer::CreateManualResetTimer();
+  result = Wait(timer.get(), false, 1ms);
+  REQUIRE(result == WaitResult::kTimeout);
+  REQUIRE(timer->SetOnce(1ms));  // Signals it
+  result = Wait(timer.get(), false, 2ms);
+  REQUIRE(result == WaitResult::kSuccess);
+  result = Wait(timer.get(), false, 1ms);
+  REQUIRE(result == WaitResult::kSuccess);  // Did not reset
+
+  // Test Synchronization
+  timer = Timer::CreateSynchronizationTimer();
+  result = Wait(timer.get(), false, 1ms);
+  REQUIRE(result == WaitResult::kTimeout);
+  REQUIRE(timer->SetOnce(1ms));  // Signals it
+  result = Wait(timer.get(), false, 2ms);
+  REQUIRE(result == WaitResult::kSuccess);
+  result = Wait(timer.get(), false, 1ms);
+  REQUIRE(result == WaitResult::kTimeout);  // Did reset
+
+  // TODO(bwrsandman): This test unexpectedly fails under windows
+  // Test long due time
+  // timer = Timer::CreateSynchronizationTimer();
+  // REQUIRE(timer->SetOnce(10s));
+  // result = Wait(timer.get(), false, 10ms);  // Still signals under windows
+  // REQUIRE(result == WaitResult::kTimeout);
+
+  // Test Repeating
+  REQUIRE(timer->SetRepeating(1ms, 10ms));
+  for (int i = 0; i < 10; ++i) {
+    result = Wait(timer.get(), false, 20ms);
+    INFO(i);
+    REQUIRE(result == WaitResult::kSuccess);
+  }
+  MaybeYield();
+  Sleep(10ms);  // Skip a few events
+  for (int i = 0; i < 10; ++i) {
+    result = Wait(timer.get(), false, 20ms);
+    REQUIRE(result == WaitResult::kSuccess);
+  }
+  // Cancel it
+  timer->Cancel();
+  result = Wait(timer.get(), false, 20ms);
+  REQUIRE(result == WaitResult::kTimeout);
+  MaybeYield();
+  Sleep(10ms);  // Skip a few events
+  result = Wait(timer.get(), false, 20ms);
+  REQUIRE(result == WaitResult::kTimeout);
+  // Cancel with SetOnce
+  REQUIRE(timer->SetRepeating(1ms, 10ms));
+  for (int i = 0; i < 10; ++i) {
+    result = Wait(timer.get(), false, 20ms);
+    REQUIRE(result == WaitResult::kSuccess);
+  }
+  REQUIRE(timer->SetOnce(1ms));
+  result = Wait(timer.get(), false, 20ms);
+  REQUIRE(result == WaitResult::kSuccess);  // Signal from Set Once
+  result = Wait(timer.get(), false, 20ms);
+  REQUIRE(result == WaitResult::kTimeout);  // No more signals from repeating
+}
+
+TEST_CASE("Wait on Multiple Timers", "Timer") {
+  WaitResult all_result;
+  std::pair<WaitResult, size_t> any_result;
+
+  auto timer0 = Timer::CreateSynchronizationTimer();
+  auto timer1 = Timer::CreateManualResetTimer();
+
+  // None signaled
+  all_result = WaitAll({timer0.get(), timer1.get()}, false, 1ms);
+  REQUIRE(all_result == WaitResult::kTimeout);
+  any_result = WaitAny({timer0.get(), timer1.get()}, false, 1ms);
+  REQUIRE(any_result.first == WaitResult::kTimeout);
+  REQUIRE(any_result.second == 0);
+
+  // Some signaled
+  REQUIRE(timer1->SetOnce(1ms));
+  all_result = WaitAll({timer0.get(), timer1.get()}, false, 100ms);
+  REQUIRE(all_result == WaitResult::kTimeout);
+  any_result = WaitAny({timer0.get(), timer1.get()}, false, 100ms);
+  REQUIRE(any_result.first == WaitResult::kSuccess);
+  REQUIRE(any_result.second == 1);
+
+  // All signaled
+  REQUIRE(timer0->SetOnce(1ms));
+  all_result = WaitAll({timer0.get(), timer1.get()}, false, 100ms);
+  REQUIRE(all_result == WaitResult::kSuccess);
+  REQUIRE(timer0->SetOnce(1ms));
+  Sleep(1ms);
+  any_result = WaitAny({timer0.get(), timer1.get()}, false, 100ms);
+  REQUIRE(any_result.first == WaitResult::kSuccess);
+  REQUIRE(any_result.second == 0);
+
+  // Check that timer0 reset
+  any_result = WaitAny({timer0.get(), timer1.get()}, false, 100ms);
+  REQUIRE(any_result.first == WaitResult::kSuccess);
+  REQUIRE(any_result.second == 1);
+}
+
+TEST_CASE("Create and Trigger Timer Callbacks", "Timer") {
+  // TODO(bwrsandman): Check which thread performs callback and timing of
+  // callback
   REQUIRE(true);
 }
 
diff --git a/src/xenia/base/threading.h b/src/xenia/base/threading.h
index 7c635fcea..790539141 100644
--- a/src/xenia/base/threading.h
+++ b/src/xenia/base/threading.h
@@ -306,12 +306,12 @@ class Timer : public WaitHandle {
                             std::chrono::milliseconds period,
                             std::function<void()> opt_callback = nullptr) = 0;
   template <typename Rep, typename Period>
-  void SetRepeating(std::chrono::nanoseconds due_time,
+  bool SetRepeating(std::chrono::nanoseconds due_time,
                     std::chrono::duration<Rep, Period> period,
                     std::function<void()> opt_callback = nullptr) {
-    SetRepeating(due_time,
-                 std::chrono::duration_cast<std::chrono::milliseconds>(period),
-                 std::move(opt_callback));
+    return SetRepeating(
+        due_time, std::chrono::duration_cast<std::chrono::milliseconds>(period),
+        std::move(opt_callback));
   }
 
   // Stops the timer before it can be set to the signaled state and cancels
diff --git a/src/xenia/base/threading_posix.cc b/src/xenia/base/threading_posix.cc
index 771154136..212286b1e 100644
--- a/src/xenia/base/threading_posix.cc
+++ b/src/xenia/base/threading_posix.cc
@@ -37,7 +37,7 @@ inline timespec DurationToTimeSpec(
 // This implementation uses the SIGRTMAX - SIGRTMIN to signal to a thread
 // gdb tip, for SIG = SIGRTMIN + SignalType : handle SIG nostop
 // lldb tip, for SIG = SIGRTMIN + SignalType : process handle SIG -s false
-enum class SignalType { kHighResolutionTimer, k_Count };
+enum class SignalType { kHighResolutionTimer, kTimer, k_Count };
 
 int GetSystemSignal(SignalType num) {
   auto result = SIGRTMIN + static_cast<int>(num);
@@ -351,6 +351,82 @@ class PosixCondition<Mutant> : public PosixConditionBase {
   std::thread::id owner_;
 };
 
+template <>
+class PosixCondition<Timer> : public PosixConditionBase {
+ public:
+  explicit PosixCondition(bool manual_reset)
+      : callback_(),
+        timer_(nullptr),
+        signal_(false),
+        manual_reset_(manual_reset) {}
+
+  virtual ~PosixCondition() { Cancel(); }
+
+  // TODO(bwrsandman): due_times of under 1ms deadlock under travis
+  bool Set(std::chrono::nanoseconds due_time, std::chrono::milliseconds period,
+           std::function<void()> opt_callback = nullptr) {
+    std::lock_guard<std::mutex> lock(mutex_);
+
+    callback_ = std::move(opt_callback);
+    signal_ = false;
+
+    // Create timer
+    if (timer_ == nullptr) {
+      sigevent sev{};
+      sev.sigev_notify = SIGEV_SIGNAL;
+      sev.sigev_signo = GetSystemSignal(SignalType::kTimer);
+      sev.sigev_value.sival_ptr = this;
+      if (timer_create(CLOCK_REALTIME, &sev, &timer_) == -1) return false;
+    }
+
+    // Start timer
+    itimerspec its{};
+    its.it_value = DurationToTimeSpec(due_time);
+    its.it_interval = DurationToTimeSpec(period);
+    return timer_settime(timer_, 0, &its, nullptr) == 0;
+  }
+
+  void CompletionRoutine() {
+    // As the callback may reset the timer, store local.
+    std::function<void()> callback;
+    {
+      std::lock_guard<std::mutex> lock(mutex_);
+      // Store callback
+      if (callback_) callback = callback_;
+      signal_ = true;
+      if (manual_reset_) {
+        cond_.notify_all();
+      } else {
+        cond_.notify_one();
+      }
+    }
+    // Call callback
+    if (callback) callback();
+  }
+
+  bool Cancel() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    bool result = true;
+    if (timer_) {
+      result = timer_delete(timer_) == 0;
+      timer_ = nullptr;
+    }
+    return result;
+  }
+
+ private:
+  inline bool signaled() const override { return signal_; }
+  inline void post_execution() override {
+    if (!manual_reset_) {
+      signal_ = false;
+    }
+  }
+  std::function<void()> callback_;
+  timer_t timer_;
+  volatile bool signal_;
+  const bool manual_reset_;
+};
+
 // Native posix thread handle
 template <typename T>
 class PosixThreadHandle : public T {
@@ -371,7 +447,7 @@ class PosixThreadHandle : public T {
 template <typename T>
 class PosixConditionHandle : public T {
  public:
-  explicit PosixConditionHandle(bool initial_owner);
+  explicit PosixConditionHandle(bool);
   PosixConditionHandle(bool manual_reset, bool initial_state);
   PosixConditionHandle(uint32_t initial_count, uint32_t maximum_count);
   ~PosixConditionHandle() override = default;
@@ -394,9 +470,8 @@ PosixConditionHandle<Mutant>::PosixConditionHandle(bool initial_owner)
     : handle_(initial_owner) {}
 
 template <>
-PosixConditionHandle<Timer>::PosixConditionHandle(bool manual_reset,
-                                                  bool initial_state)
-    : handle_() {}
+PosixConditionHandle<Timer>::PosixConditionHandle(bool manual_reset)
+    : handle_(manual_reset) {}
 
 template <>
 PosixConditionHandle<Event>::PosixConditionHandle(bool manual_reset,
@@ -488,35 +563,30 @@ std::unique_ptr<Mutant> Mutant::Create(bool initial_owner) {
   return std::make_unique<PosixMutant>(initial_owner);
 }
 
-// TODO(dougvj)
 class PosixTimer : public PosixConditionHandle<Timer> {
  public:
-  PosixTimer(bool manual_reset) : PosixConditionHandle(manual_reset, false) {
-    assert_always();
-  }
-  ~PosixTimer() = default;
+  explicit PosixTimer(bool manual_reset) : PosixConditionHandle(manual_reset) {}
+  ~PosixTimer() override = default;
   bool SetOnce(std::chrono::nanoseconds due_time,
                std::function<void()> opt_callback) override {
-    assert_always();
-    return false;
+    return handle_.Set(due_time, std::chrono::milliseconds::zero(),
+                       std::move(opt_callback));
   }
   bool SetRepeating(std::chrono::nanoseconds due_time,
                     std::chrono::milliseconds period,
                     std::function<void()> opt_callback) override {
-    assert_always();
-    return false;
-  }
-  bool Cancel() override {
-    assert_always();
-    return false;
+    return handle_.Set(due_time, period, std::move(opt_callback));
   }
+  bool Cancel() override { return handle_.Cancel(); }
 };
 
 std::unique_ptr<Timer> Timer::CreateManualResetTimer() {
+  install_signal_handler(SignalType::kTimer);
   return std::make_unique<PosixTimer>(true);
 }
 
 std::unique_ptr<Timer> Timer::CreateSynchronizationTimer() {
+  install_signal_handler(SignalType::kTimer);
   return std::make_unique<PosixTimer>(false);
 }
 
@@ -628,6 +698,12 @@ static void signal_handler(int signal, siginfo_t* info, void* /*context*/) {
           *static_cast<std::function<void()>*>(info->si_value.sival_ptr);
       callback();
     } break;
+    case SignalType::kTimer: {
+      assert_not_null(info->si_value.sival_ptr);
+      auto pTimer =
+          static_cast<PosixCondition<Timer>*>(info->si_value.sival_ptr);
+      pTimer->CompletionRoutine();
+    } break;
     default:
       assert_always();
   }