diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f5be4b6140c..1d04f653238 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -32,6 +32,7 @@ jobs:
         os:
           - ubuntu-latest
           - windows-latest
+          - macos-latest
         crypto:
           - mbedtls
           - openssl
@@ -59,6 +60,16 @@ jobs:
             toolchain: VS2019
           - os: ubuntu-latest
             arch: ia32
+          - os: macos-latest
+            arch: ia32
+          - os: macos-latest
+            toolchain: GCC
+          - os: macos-latest
+            toolchain: VS2019
+          - os: macos-latest
+            toolchain: ARM_GNU
+          - os: macos-latest
+            toolchain: LIBFUZZER
           - os: windows-latest
             toolchain: GCC
             arch: ia32
@@ -113,7 +124,7 @@ jobs:
         with:
           arch: x86
       - name:  Toolchain Setup - Clang
-        if:  matrix.toolchain == 'CLANG' || matrix.toolchain == 'LIBFUZZER' && matrix.os == 'ubuntu-latest'
+        if:  (matrix.toolchain == 'CLANG' || matrix.toolchain == 'LIBFUZZER') && matrix.os == 'ubuntu-latest'
         run: |
           sudo apt-get update
           sudo apt-get install llvm
@@ -151,6 +162,16 @@ jobs:
           make copy_sample_key
           make copy_seed
           make -j`nproc`
+      - name: Build - Darwin
+        if: matrix.os == 'macos-latest'
+        run: |
+          mkdir -p build
+          cd build
+          cmake --version
+          cmake -E env CFLAGS="${{ matrix.configurations }} -DLIBSPDM_DEBUG_LIBSPDM_ASSERT_CONFIG=3" cmake -DARCH=${{ matrix.arch }} -DTOOLCHAIN=${{ matrix.toolchain }} -DTARGET=${{ matrix.target }} -DCRYPTO=${{ matrix.crypto }} ..
+          make copy_sample_key
+          make copy_seed
+          make # process killed with multicore
       - name: Build - Windows
         if: matrix.os == 'windows-latest' && matrix.toolchain != 'GCC'
         run: |
@@ -179,6 +200,16 @@ jobs:
           cmake -DARCH=x64 -DTOOLCHAIN=GCC -DTARGET=Debug -DCRYPTO=${{matrix.crypto}} -DGCOV=ON ..
           make copy_sample_key
           make -j`nproc`
+      - name: Build - Darwin - GCONV=ON
+        if: matrix.os == 'macos-latest'
+        run: |
+          mkdir -p build
+          cd build
+          cmake --version
+          cmake -DARCH=x64 -DTOOLCHAIN=CLANG -DTARGET=Debug -DCRYPTO=${{matrix.crypto}} -DGCOV=ON ..
+          make copy_sample_key
+          make copy_seed
+          make # process killed with multicore
       - name: Test Requester
         if: matrix.toolchain != 'LIBFUZZER' && matrix.toolchain != 'ARM_GNU' && matrix.configurations != '-DDISABLE_TESTS=1'
         run: |
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6b0c4e749fc..91a3271c58a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -136,6 +136,12 @@ if(CMAKE_SYSTEM_NAME MATCHES "Linux")
     if(STACK_USAGE STREQUAL "ON")
         message("STACK_USAGE = ON")
     endif()
+elseif (CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    if (TOOLCHAIN STREQUAL "CLANG")
+        message("TOOLCHAIN = CLANG")
+    else()
+        message(FATAL_ERROR "Unknown TOOLCHAIN")
+    endif()
 elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
     if(TOOLCHAIN STREQUAL "GCC")
         message("TOOLCHAIN = GCC")
@@ -680,7 +686,19 @@ if(CMAKE_SYSTEM_NAME MATCHES "Linux")
         add_compile_options(-m32)
         set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32" )
     endif()
+elseif(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    if (TOOLCHAIN STREQUAL "CLANG")
+        set(CMAKE_C_COMPILER clang)
+        add_compile_options(-g -Og -fshort-wchar -fno-strict-aliasing -Wall  -Wno-array-bounds -ffunction-sections -fdata-sections -fno-common -Wno-address -fpie -fno-asynchronous-unwind-tables)
+
+        set(MBEDTLS_FLAGS "")
+        set(OPENSSL_FLAGS -include base.h -Wno-error=maybe-uninitialized -Wno-error=format -Wno-format -Wno-error=unused-but-set-variable)
+        set(CMOCKA_FLAGS -std=gnu99 -Wpedantic -Wall -Wshadow -Wmissing-prototypes -Wcast-align -Werror=address -Wstrict-prototypes -Werror=strict-prototypes -Wwrite-strings -Werror=write-strings -Werror-implicit-function-declaration -Wpointer-arith -Werror=pointer-arith -Wdeclaration-after-statement -Werror=declaration-after-statement -Wreturn-type -Werror=return-type -Wuninitialized -Werror=uninitialized -Werror=strict-overflow -Wstrict-overflow=2 -Wno-format-zero-length -Wmissing-field-initializers -Wformat-security -Werror=format-security -fno-common -Wformat -fno-common -fstack-protector-strong)
 
+        set(CMAKE_LINKER clang)
+        set(CMAKE_EXE_LINKER_FLAGS "-Wno-error")
+        set(CMAKE_C_LINK_EXECUTABLE "<CMAKE_LINKER> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
+    endif()
 elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
     if(TOOLCHAIN STREQUAL "GCC")
         set(CMAKE_C_COMPILER gcc)
@@ -879,7 +897,7 @@ set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
 add_custom_target(copy_sample_key)
 
 execute_process(COMMAND uname OUTPUT_VARIABLE uname)
-if(CMAKE_SYSTEM_NAME MATCHES "Linux" OR uname MATCHES "^MINGW")
+if(CMAKE_SYSTEM_NAME MATCHES "Linux" OR uname MATCHES "^MINGW" OR CMAKE_SYSTEM_NAME MATCHES "Darwin")
     add_custom_command(TARGET copy_sample_key
                     PRE_BUILD
                     COMMAND cp -r -f ${LIBSPDM_DIR}/unit_test/sample_key/* ${EXECUTABLE_OUTPUT_PATH})
@@ -901,7 +919,7 @@ endif()
 
 add_custom_target(copy_seed)
 
-if(CMAKE_SYSTEM_NAME MATCHES "Linux" OR uname MATCHES "^MINGW")
+if(CMAKE_SYSTEM_NAME MATCHES "Linux" OR uname MATCHES "^MINGW" OR CMAKE_SYSTEM_NAME MATCHES "Darwin")
     add_custom_command(TARGET copy_seed
                     PRE_BUILD
                     COMMAND cp -r -f ${LIBSPDM_DIR}/unit_test/fuzzing/seeds ${EXECUTABLE_OUTPUT_PATH}
diff --git a/os_stub/platform_lib/CMakeLists.txt b/os_stub/platform_lib/CMakeLists.txt
index 0277762fc59..11a9be6edca 100644
--- a/os_stub/platform_lib/CMakeLists.txt
+++ b/os_stub/platform_lib/CMakeLists.txt
@@ -11,7 +11,7 @@ target_include_directories(platform_lib
 if(CMAKE_SYSTEM_NAME MATCHES "Linux" AND (NOT TOOLCHAIN STREQUAL "ARM_DS2022") AND (NOT TOOLCHAIN STREQUAL "RISCV_XPACK")  AND (NOT TOOLCHAIN STREQUAL "ARM_GNU_BARE_METAL"))
     target_sources(platform_lib
         PRIVATE
-        time_linux.c
+        time_unix.c
         watchdog.c
     )
 elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
@@ -20,10 +20,16 @@ elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
         time_win.c
         watchdog.c
     )
+elseif(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    target_sources(platform_lib
+        PRIVATE
+        time_unix.c
+        watchdog.c
+    )
 else()
     target_sources(platform_lib
         PRIVATE
         time_sample.c
         watchdog.c
     )
-endif()
\ No newline at end of file
+endif()
diff --git a/os_stub/platform_lib/time_linux.c b/os_stub/platform_lib/time_unix.c
similarity index 100%
rename from os_stub/platform_lib/time_linux.c
rename to os_stub/platform_lib/time_unix.c
diff --git a/os_stub/platform_lib_null/CMakeLists.txt b/os_stub/platform_lib_null/CMakeLists.txt
index 7007070acc3..5a58836f5ac 100644
--- a/os_stub/platform_lib_null/CMakeLists.txt
+++ b/os_stub/platform_lib_null/CMakeLists.txt
@@ -11,7 +11,7 @@ target_include_directories(platform_lib_null
 if(CMAKE_SYSTEM_NAME MATCHES "Linux")
     target_sources(platform_lib_null
         PRIVATE
-            time_linux.c
+            time_unix.c
             watchdog.c
     )
 elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
@@ -20,6 +20,11 @@ elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
             time_win.c
             watchdog.c
     )
+elseif(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    target_sources(platform_lib_null
+        PRIVATE
+            time_unix.c
+            watchdog.c
+    )
 
 endif()
-
diff --git a/os_stub/platform_lib_null/time_linux.c b/os_stub/platform_lib_null/time_unix.c
similarity index 100%
rename from os_stub/platform_lib_null/time_linux.c
rename to os_stub/platform_lib_null/time_unix.c