diff --git a/CMakeLists.txt b/CMakeLists.txt
index f351fe1cd82..16869142c47 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1607,6 +1607,7 @@ elseif(CMAKE_C_COMPILER_ID MATCHES "MSVC")
     # warning level:
     "/W3"
     "/w34062"  # switch statement contains 'default' but no 'case' labels
+    "/w34100"  # 'identifier' : unreferenced formal parameter
     "/w34115"  # 'type' : named type definition in parentheses
     "/w34189"  # local variable is initialized but not referenced
     # see https://docs.microsoft.com/en-us/cpp/error-messages/compiler-warnings/c5038?view=vs-2017
diff --git a/build_files/cmake/macros.cmake b/build_files/cmake/macros.cmake
index 958c8205bfd..92e36767cad 100644
--- a/build_files/cmake/macros.cmake
+++ b/build_files/cmake/macros.cmake
@@ -702,6 +702,7 @@ macro(remove_strict_flags)
   endif()
 
   if(MSVC)
+    remove_cc_flag(/w34100) # Restore warn C4100 (unreferenced formal parameter) back to w4
     remove_cc_flag(/w34189) # Restore warn C4189 (unused variable) back to w4
   endif()
 
@@ -721,7 +722,7 @@ macro(remove_extra_strict_flags)
   endif()
 
   if(MSVC)
-    # TODO
+    remove_cc_flag(/w34100) # Restore warn C4100 (unreferenced formal parameter) back to w4
   endif()
 endmacro()
 
diff --git a/intern/guardedalloc/intern/mallocn_intern.h b/intern/guardedalloc/intern/mallocn_intern.h
index c2e9f9117bc..14e5c171e7e 100644
--- a/intern/guardedalloc/intern/mallocn_intern.h
+++ b/intern/guardedalloc/intern/mallocn_intern.h
@@ -10,6 +10,9 @@
 
 #ifdef __GNUC__
 #  define UNUSED(x) UNUSED_##x __attribute__((__unused__))
+#elif defined(_MSC_VER)
+/* NOTE: This suppresses the warning for the line, not the attribute. */
+#  define UNUSED(x) UNUSED_##x __pragma(warning(suppress : 4100))
 #else
 #  define UNUSED(x) UNUSED_##x
 #endif
diff --git a/intern/mantaflow/CMakeLists.txt b/intern/mantaflow/CMakeLists.txt
index 60ca19c35ff..7a92301b9ed 100644
--- a/intern/mantaflow/CMakeLists.txt
+++ b/intern/mantaflow/CMakeLists.txt
@@ -15,6 +15,13 @@ if(WIN32)
   add_definitions(-D_USE_MATH_DEFINES)
 endif()
 
+if(WIN32)
+  # Some files in extern are being included which brings up a bunch of
+  # "unreferenced formal parameter" warnings.
+  # So restore warn C4100 (unreferenced formal parameter) back to w4
+  remove_cc_flag(/w34100)
+endif()
+
 
 set(INC
   extern
diff --git a/source/blender/blenlib/BLI_utildefines.h b/source/blender/blenlib/BLI_utildefines.h
index e03bc7ba78a..35e3345f4c2 100644
--- a/source/blender/blenlib/BLI_utildefines.h
+++ b/source/blender/blenlib/BLI_utildefines.h
@@ -668,6 +668,9 @@ extern bool BLI_memory_is_zero(const void *arr, size_t arr_size);
 /* UNUSED macro, for function argument */
 #  if defined(__GNUC__) || defined(__clang__)
 #    define UNUSED(x) UNUSED_##x __attribute__((__unused__))
+#  elif defined(_MSC_VER)
+/* NOTE: This suppresses the warning for the line, not the attribute. */
+#    define UNUSED(x) UNUSED_##x __pragma(warning(suppress : 4100))
 #  else
 #    define UNUSED(x) UNUSED_##x
 #  endif
diff --git a/source/blender/io/usd/CMakeLists.txt b/source/blender/io/usd/CMakeLists.txt
index 21017d1be88..568ed4c7641 100644
--- a/source/blender/io/usd/CMakeLists.txt
+++ b/source/blender/io/usd/CMakeLists.txt
@@ -35,6 +35,13 @@ if(USD_IMAGING_HEADERS)
   add_definitions(-DUSD_HAS_IMAGING)
 endif()
 
+if(WIN32)
+  # Some USD library headers trigger the "unreferenced formal parameter"
+  # warning alert.
+  # Silence them by restore warn C4100 back to w4
+  remove_cc_flag(/w34100)
+endif()
+
 set(INC
   .
   ../common
diff --git a/source/blender/makesrna/intern/CMakeLists.txt b/source/blender/makesrna/intern/CMakeLists.txt
index 2988b7e2e35..98c2b2e53fd 100644
--- a/source/blender/makesrna/intern/CMakeLists.txt
+++ b/source/blender/makesrna/intern/CMakeLists.txt
@@ -140,6 +140,9 @@ if(CMAKE_COMPILER_IS_GNUCC OR (CMAKE_C_COMPILER_ID MATCHES "Clang"))
 endif()
 if(CMAKE_C_COMPILER_ID MATCHES "Clang")
   string(APPEND GENSRC_CFLAGS " -Wno-missing-variable-declarations")
+elseif(MSVC)
+  # Restore warn C4100 (unreferenced formal parameter) back to w4
+  remove_cc_flag(/w34100)
 endif()
 
 if(GENSRC_CFLAGS)
diff --git a/source/blender/python/intern/stubs.c b/source/blender/python/intern/stubs.c
index f860bdc36ee..6ac9cd64f33 100644
--- a/source/blender/python/intern/stubs.c
+++ b/source/blender/python/intern/stubs.c
@@ -12,6 +12,9 @@
 #if defined(__GNUC__) || defined(__clang__)
 #  pragma GCC diagnostic error "-Wmissing-prototypes"
 #  pragma GCC diagnostic ignored "-Wunused-parameter"
+#elif defined(_MSC_VER)
+/* Suppress unreferenced formal parameter warning. */
+#  pragma warning(disable : 4100)
 #endif
 
 /* python, will come back */