diff --git a/CMakeLists.txt b/CMakeLists.txt
index d78d2613251c..0b88247df27a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -388,9 +388,9 @@ cmake_dependent_option(USE_PRIORITIZED_TEXT_FOR_LD "Use prioritized text linker
 
 option(USE_MIMALLOC "Use mimalloc" OFF)
 # Enable third party mimalloc library to improve memory allocation performance
-# on Windows.
+# on Windows and AArch64.
 option(USE_MIMALLOC_ON_MKL "Use mimalloc on MKL" OFF)
-if(WIN32)
+if(WIN32 OR (CPU_AARCH64 AND NOT APPLE))
   set(USE_MIMALLOC ON)
 
   # Not enable USE_MIMALLOC_ON_MKL due to it caused issue:
diff --git a/c10/core/impl/alloc_cpu.cpp b/c10/core/impl/alloc_cpu.cpp
index 791104690cd8..c1b7ca858632 100644
--- a/c10/core/impl/alloc_cpu.cpp
+++ b/c10/core/impl/alloc_cpu.cpp
@@ -108,12 +108,15 @@ void* alloc_cpu(size_t nbytes) {
       "DefaultCPUAllocator: not enough memory: you tried to allocate ",
       nbytes,
       " bytes.");
-#elif defined(_MSC_VER)
-#ifdef USE_MIMALLOC
+#elif defined(USE_MIMALLOC)
   data = mi_malloc_aligned(nbytes, gAlignment);
-#else
+  CAFFE_ENFORCE(
+      data,
+      "DefaultCPUAllocator: not enough memory: you tried to allocate ",
+      nbytes,
+      " bytes.");
+#elif defined(_MSC_VER)
   data = _aligned_malloc(nbytes, gAlignment);
-#endif
   CAFFE_ENFORCE(
       data,
       "DefaultCPUAllocator: not enough memory: you tried to allocate ",
@@ -160,12 +163,10 @@ void* alloc_cpu(size_t nbytes) {
 }
 
 void free_cpu(void* data) {
-#ifdef _MSC_VER
 #ifdef USE_MIMALLOC
   mi_free(data);
-#else
+#elif defined(_MSC_VER)
   _aligned_free(data);
-#endif
 #else
   // NOLINTNEXTLINE(cppcoreguidelines-no-malloc)
   free(data);
diff --git a/setup.py b/setup.py
index 9f2eae6f6a90..bdfab24a0b32 100644
--- a/setup.py
+++ b/setup.py
@@ -225,7 +225,7 @@
 #
 #   USE_MIMALLOC
 #      Static link mimalloc into C10, and use mimalloc in alloc_cpu & alloc_free.
-#      By default, It is only enabled on Windows.
+#      By default, It is only enabled on Windows and AArch64.
 #
 #   BUILD_LIBTORCH_WHL
 #      Builds libtorch.so and its dependencies as a wheel