diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 82bfedb93d..179689b774 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -538,7 +538,7 @@ if (MSVC)
       set(CMAKE_ASM_MASM_FLAGS "${CMAKE_ASM_MASM_FLAGS} /safeseh")
     endif()
   endif()
-  
+
 
   #Always enable exception handling, even for Windows ARM
   if(NOT onnxruntime_DISABLE_EXCEPTIONS)
@@ -831,7 +831,13 @@ get_filename_component(ORTTRAINING_ROOT "${ORTTRAINING_ROOT}" ABSOLUTE)
 get_filename_component(REPO_ROOT "${REPO_ROOT}" ABSOLUTE)
 set(ONNXRUNTIME_INCLUDE_DIR ${REPO_ROOT}/include/onnxruntime)
 
-add_subdirectory(external/date EXCLUDE_FROM_ALL)
+if(onnxruntime_PREFER_SYSTEM_LIB)
+  find_package(date)
+  add_library(date_interface ALIAS date::date)
+endif()
+if(NOT TARGET date::date)
+  add_subdirectory(external/date EXCLUDE_FROM_ALL)
+endif()
 
 set(SAFEINT_INCLUDE_DIR ${REPO_ROOT}/cmake/external/SafeInt)
 add_library(safeint_interface INTERFACE)
@@ -842,7 +848,12 @@ if(onnxruntime_DISABLE_EXCEPTIONS)
   add_compile_definitions(optional_CONFIG_NO_EXCEPTIONS=1)
 endif()
 
-add_subdirectory(external/mp11 EXCLUDE_FROM_ALL)
+if(onnxruntime_PREFER_SYSTEM_LIB)
+  find_package(boost_mp11)
+endif()
+if(NOT TARGET Boost::mp11)
+  add_subdirectory(external/mp11 EXCLUDE_FROM_ALL)
+endif()
 
 set(JSON_BuildTests OFF CACHE INTERNAL "")
 set(JSON_Install OFF CACHE INTERNAL "")
@@ -883,12 +894,12 @@ else()
         elseif(WINDOWS_STORE OR (WIN32 AND NOT CMAKE_CXX_STANDARD_LIBRARIES MATCHES kernel32.lib))
             message(WARNING "Cpuinfo not included in Windows Store or WCOS builds")
             set(CPUINFO_SUPPORTED FALSE)
-        endif()     
+        endif()
     elseif(NOT ${onnxruntime_target_platform} MATCHES "^(i[3-6]86|AMD64|x86(_64)?|armv[5-8].*|aarch64|arm64)$")
         message(WARNING
         "Target processor architecture \"${onnxruntime_target_platform}\" is not supported in cpuinfo. "
         "cpuinfo not included.")
-        set(CPUINFO_SUPPORTED FALSE)    
+        set(CPUINFO_SUPPORTED FALSE)
     endif()
 endif()
 
@@ -905,7 +916,7 @@ if(CPUINFO_SUPPORTED)
       set(IOS ON CACHE INTERNAL "")
       set(IOS_ARCH "${CMAKE_OSX_ARCHITECTURES}" CACHE INTERNAL "")
   endif()
-  
+
   string(APPEND CMAKE_CXX_FLAGS " -DCPUINFO_SUPPORTED")
   add_subdirectory(external/pytorch_cpuinfo EXCLUDE_FROM_ALL)
   if(MSVC)
@@ -1412,7 +1423,13 @@ set(FLATBUFFERS_INSTALL OFF CACHE BOOL "FLATBUFFERS_INSTALL" FORCE)
 set(FLATBUFFERS_BUILD_FLATHASH OFF CACHE BOOL "FLATBUFFERS_BUILD_FLATHASH" FORCE)
 set(FLATBUFFERS_BUILD_FLATLIB ON CACHE BOOL "FLATBUFFERS_BUILD_FLATLIB" FORCE)
 set_msvc_c_cpp_compiler_warning_level(4)
-add_subdirectory(external/flatbuffers EXCLUDE_FROM_ALL)
+if(onnxruntime_PREFER_SYSTEM_LIB)
+  find_package(Flatbuffers)
+  add_library(flatbuffers ALIAS flatbuffers::flatbuffers)
+endif()
+if(NOT TARGET flatbuffers::flatbuffers)
+  add_subdirectory(external/flatbuffers EXCLUDE_FROM_ALL)
+endif()
 set_msvc_c_cpp_compiler_warning_level(3)
 list(APPEND onnxruntime_EXTERNAL_DEPENDENCIES flatbuffers)
 list(APPEND onnxruntime_EXTERNAL_LIBRARIES flatbuffers)