diff --git a/Doc/c-api/intro.rst b/Doc/c-api/intro.rst
index 701d2a31b8c905..5f1c87c5aa72a6 100644
--- a/Doc/c-api/intro.rst
+++ b/Doc/c-api/intro.rst
@@ -227,6 +227,10 @@ The following macros are for common tasks not specific to Python.
    Use this for unused arguments in a function definition to silence compiler
    warnings. Example: ``int func(int a, int Py_UNUSED(b)) { return a; }``.
 
+   The macro mangles *name* so that it cannot be used, and when possible,
+   applies the C23/C++17 attribute ``[[maybe_unused]]`` or a compiler-specific
+   equivalent.
+
    .. versionadded:: 3.4
 
 .. c:macro:: Py_GCC_ATTRIBUTE(name)
diff --git a/Include/pymacro.h b/Include/pymacro.h
index 41dfd9155b9b24..aa2ce507a83d9a 100644
--- a/Include/pymacro.h
+++ b/Include/pymacro.h
@@ -254,7 +254,9 @@
  *
  * int func(int a, int Py_UNUSED(b)) { return a; }
  */
-#if defined(__GNUC__) || defined(__clang__)
+#if _Py__has_c_cpp_attribute(maybe_unused)
+#  define Py_UNUSED(name) _unused_ ## name _Py_C_ATTRIBUTE(maybe_unused)
+#elif defined(__GNUC__) || defined(__clang__)
 #  define Py_UNUSED(name) _unused_ ## name __attribute__((unused))
 #elif defined(_MSC_VER)
    // Disable warning C4100: unreferenced formal parameter,
diff --git a/Include/pyport.h b/Include/pyport.h
index 1af2b61eeacd28..503959bfcd7388 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -27,6 +27,52 @@
 #  define _Py__has_attribute(x) 0
 #endif
 
+// Same check for C23 [[attribute]].
+#ifdef __has_c_attribute
+#  define _Py__has_c_attribute(X) __has_c_attribute(X)
+#else
+#  define _Py__has_c_attribute(X) 0
+#endif
+
+// Same check for C++17 [[attribute]].
+#if defined(__cpp_attributes) && defined(__has_cpp_attribute)
+#  define _Py__has_cpp_attribute(X) __has_cpp_attribute(X)
+#else
+#  define _Py__has_cpp_attribute(X) 0
+#endif
+
+// Combined check for C & C++ [[attribute]]. Only use if attribute works
+// the same way in both languages.
+#ifdef __cplusplus
+#  define _Py__has_c_cpp_attribute(X) _Py__has_cpp_attribute(X)
+#else
+#  define _Py__has_c_cpp_attribute(X) _Py__has_c_attribute(X)
+#endif
+
+// _Py_C_ATTRIBUTE(attribute): wrapper for [[attribute]]
+#if defined(__GNUC__) && !defined(__clang__) && defined(__STDC_VERSION__) && __STDC_VERSION__ < 202311L
+// In GCC pedantic mode before C23, `__has_c_attribute` is defined but using
+// C attributes emits warnings. Suppress them.
+#  define _Py_C_ATTRIBUTE(ATTR) [[__extension__ ATTR]]
+#elif defined(__clang__) && defined(__STDC_VERSION__) && __STDC_VERSION__ < 202311L
+// Similar for clang and C23. It's not clear how to suppress this,
+// so pretend the feature is missing.
+#  undef _Py__has_cpp_attribute
+#  undef _Py__has_c_cpp_attribute
+#  define _Py__has_cpp_attribute(X) 0
+#  define _Py__has_c_cpp_attribute(X) 0
+#  define _Py_C_ATTRIBUTE(ATTR)
+#elif defined(__clang__) && defined(__cplusplus) && __cplusplus < 201703L
+// Same for clang and C++17.
+#  undef _Py__has_c_attribute
+#  undef _Py__has_c_cpp_attribute
+#  define _Py__has_c_attribute(X) 0
+#  define _Py__has_c_cpp_attribute(X) 0
+#  define _Py_C_ATTRIBUTE(ATTR)
+#else
+#  define _Py_C_ATTRIBUTE(ATTR) [[ATTR]]
+#endif
+
 // Macro to use C++ static_cast<> in the Python C API.
 #ifdef __cplusplus
 #  define _Py_STATIC_CAST(type, expr) static_cast<type>(expr)