diff --git a/Include/pyport.h b/Include/pyport.h
index 61e2317976eed1..a489851e57a87d 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -282,6 +282,8 @@ extern "C" {
 #elif defined(_MSC_VER)
 #define Py_DEPRECATED(VERSION) __declspec(deprecated( \
                                           "deprecated in " #VERSION))
+#elif __STDC_VERSION__ >= 202311L || __cplusplus >= 201402L
+#define Py_DEPRECATED(VERSION) [[deprecated("Deprecated in "#VERSION)]]
 #else
 #define Py_DEPRECATED(VERSION_UNUSED)
 #endif
@@ -642,6 +644,30 @@ extern "C" {
 #  endif
 #endif
 
+#ifndef PY_CXX_CONSTEXPR
+#  if defined(__cplusplus) || __STDC_VERSION__ >= 202311L
+#    define PY_CXX_CONSTEXPR constexpr
+#  else
+#    define PY_CXX_CONSTEXPR
+#  endif
+#endif
+
+#ifndef PY_CXX_CONSTEVAL
+#  ifdef __cpp_consteval
+#    define PY_CXX_CONSTEVAL consteval
+#  else
+#    define PY_CXX_CONSTEVAL
+#  endif
+#endif
+
+#ifndef PY_CXX_CONSTINIT
+#  ifdef __cpp_constinit
+#    define PY_CXX_CONSTINIT constinit
+#  else
+#    define PY_CXX_CONSTINIT
+#  endif
+#endif
+
 #if defined(__sgi) && !defined(_SGI_MP_SOURCE)
 #  define _SGI_MP_SOURCE
 #endif
diff --git a/Misc/NEWS.d/next/C_API/2026-01-02-13-46-01.gh-issue-143353.Hy-0xm.rst b/Misc/NEWS.d/next/C_API/2026-01-02-13-46-01.gh-issue-143353.Hy-0xm.rst
new file mode 100644
index 00000000000000..dc91e9f7f99e6b
--- /dev/null
+++ b/Misc/NEWS.d/next/C_API/2026-01-02-13-46-01.gh-issue-143353.Hy-0xm.rst
@@ -0,0 +1 @@
+Add macros for annotating functions with constexpr, consteval, and constinit