diff --git a/Doc/c-api/intro.rst b/Doc/c-api/intro.rst
index 76d7d5793428f8..9634e053527054 100644
--- a/Doc/c-api/intro.rst
+++ b/Doc/c-api/intro.rst
@@ -832,6 +832,13 @@ It is also implied by the presence of the
 not-Python-specific :c:macro:`!_DEBUG` macro.  When :c:macro:`!Py_DEBUG` is enabled
 in the Unix build, compiler optimization is disabled.
 
+.. note::
+   On Windows, the :c:macro:`!Py_DEBUG` macro is not defined by default.
+
+   The :option:`--with-pydebug` option is not available on Windows. Instead, the
+   not-Python-specific :c:macro:`!_DEBUG` macro can be defined by the compiler
+   options and that will enable the :c:macro:`!Py_DEBUG` macro.
+
 In addition to the reference count debugging described below, extra checks are
 performed, see :ref:`Python Debug Build <debug-build>`.
 
diff --git a/Include/internal/pycore_importdl.h b/Include/internal/pycore_importdl.h
index 525a16f6b97274..3ba9229cc21378 100644
--- a/Include/internal/pycore_importdl.h
+++ b/Include/internal/pycore_importdl.h
@@ -107,7 +107,7 @@ extern int _PyImport_RunModInitFunc(
 #include <windows.h>
 typedef FARPROC dl_funcptr;
 
-#ifdef _DEBUG
+#ifdef Py_DEBUG
 #  define PYD_DEBUG_SUFFIX "_d"
 #else
 #  define PYD_DEBUG_SUFFIX ""
diff --git a/Misc/NEWS.d/next/Windows/2025-03-31-15-37-57.gh-issue-131942.jip_aL.rst b/Misc/NEWS.d/next/Windows/2025-03-31-15-37-57.gh-issue-131942.jip_aL.rst
new file mode 100644
index 00000000000000..837f7265bba246
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2025-03-31-15-37-57.gh-issue-131942.jip_aL.rst
@@ -0,0 +1 @@
+Use the Python-specific :c:macro:`Py_DEBUG` macro rather than :c:macro:`!_DEBUG` in Windows-related C code. Patch by Xuehai Pan.
diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 158422fb9b0471..b316706be84481 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -92,7 +92,7 @@ module _ctypes
 #include <sanitizer/msan_interface.h>
 #endif
 
-#if defined(_DEBUG) || defined(__MINGW32__)
+#if defined(Py_DEBUG) || defined(__MINGW32__)
 /* Don't use structured exception handling on Windows if this is defined.
    MingW, AFAIK, doesn't support it.
 */
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index e6bfbe46add9e9..75f97ecd6b1954 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -4427,7 +4427,7 @@ _ssl__SSLContext_load_dh_params_impl(PySSLContext *self, PyObject *filepath)
     FILE *f;
     DH *dh;
 
-#if defined(MS_WINDOWS) && defined(_DEBUG)
+#if defined(MS_WINDOWS) && defined(Py_DEBUG)
     PyErr_SetString(PyExc_NotImplementedError,
                     "load_dh_params: unavailable on Windows debug build");
     return NULL;
diff --git a/Modules/_ssl/debughelpers.c b/Modules/_ssl/debughelpers.c
index 7c0b4876f4353a..f0a0a1674f32bd 100644
--- a/Modules/_ssl/debughelpers.c
+++ b/Modules/_ssl/debughelpers.c
@@ -175,7 +175,7 @@ _PySSLContext_set_keylog_filename(PyObject *op, PyObject *arg,
     PySSLContext *self = PySSLContext_CAST(op);
     FILE *fp;
 
-#if defined(MS_WINDOWS) && defined(_DEBUG)
+#if defined(MS_WINDOWS) && defined(Py_DEBUG)
     PyErr_SetString(PyExc_NotImplementedError,
                     "set_keylog_filename: unavailable on Windows debug build");
     return -1;
diff --git a/PC/clinic/msvcrtmodule.c.h b/PC/clinic/msvcrtmodule.c.h
index a77d0855af293f..8cb1a5b5c6efa9 100644
--- a/PC/clinic/msvcrtmodule.c.h
+++ b/PC/clinic/msvcrtmodule.c.h
@@ -517,7 +517,7 @@ msvcrt_ungetwch(PyObject *module, PyObject *arg)
 
 #endif /* defined(MS_WINDOWS_DESKTOP) */
 
-#if defined(_DEBUG)
+#if defined(Py_DEBUG)
 
 PyDoc_STRVAR(msvcrt_CrtSetReportFile__doc__,
 "CrtSetReportFile($module, type, file, /)\n"
@@ -562,9 +562,9 @@ msvcrt_CrtSetReportFile(PyObject *module, PyObject *const *args, Py_ssize_t narg
     return return_value;
 }
 
-#endif /* defined(_DEBUG) */
+#endif /* defined(Py_DEBUG) */
 
-#if defined(_DEBUG)
+#if defined(Py_DEBUG)
 
 PyDoc_STRVAR(msvcrt_CrtSetReportMode__doc__,
 "CrtSetReportMode($module, type, mode, /)\n"
@@ -609,9 +609,9 @@ msvcrt_CrtSetReportMode(PyObject *module, PyObject *const *args, Py_ssize_t narg
     return return_value;
 }
 
-#endif /* defined(_DEBUG) */
+#endif /* defined(Py_DEBUG) */
 
-#if defined(_DEBUG)
+#if defined(Py_DEBUG)
 
 PyDoc_STRVAR(msvcrt_set_error_mode__doc__,
 "set_error_mode($module, mode, /)\n"
@@ -648,7 +648,7 @@ msvcrt_set_error_mode(PyObject *module, PyObject *arg)
     return return_value;
 }
 
-#endif /* defined(_DEBUG) */
+#endif /* defined(Py_DEBUG) */
 
 #if (defined(MS_WINDOWS_DESKTOP) || defined(MS_WINDOWS_APP) || defined(MS_WINDOWS_SYSTEM))
 
@@ -731,4 +731,4 @@ msvcrt_SetErrorMode(PyObject *module, PyObject *arg)
 #ifndef MSVCRT_GETERRORMODE_METHODDEF
     #define MSVCRT_GETERRORMODE_METHODDEF
 #endif /* !defined(MSVCRT_GETERRORMODE_METHODDEF) */
-/*[clinic end generated code: output=692c6f52bb9193ce input=a9049054013a1b77]*/
+/*[clinic end generated code: output=5cbbc70157dcfaed input=a9049054013a1b77]*/
diff --git a/PC/launcher.c b/PC/launcher.c
index 47fafbc3bf6bad..40e6630b82e17a 100644
--- a/PC/launcher.c
+++ b/PC/launcher.c
@@ -140,7 +140,7 @@ static wchar_t * get_env(wchar_t * key)
     return buf;
 }
 
-#if defined(_DEBUG)
+#if defined(Py_DEBUG)
 /* Do not define EXECUTABLEPATH_VALUE in debug builds as it'll
    never point to the debug build. */
 #if defined(_WINDOWS)
diff --git a/PC/msvcrtmodule.c b/PC/msvcrtmodule.c
index b170e06b47dd59..60b53cb39aaf4d 100644
--- a/PC/msvcrtmodule.c
+++ b/PC/msvcrtmodule.c
@@ -415,7 +415,7 @@ msvcrt_ungetwch_impl(PyObject *module, int unicode_char)
 
 #endif /* MS_WINDOWS_DESKTOP */
 
-#ifdef _DEBUG
+#ifdef Py_DEBUG
 /*[clinic input]
 msvcrt.CrtSetReportFile -> HANDLE
 
@@ -490,7 +490,7 @@ msvcrt_set_error_mode_impl(PyObject *module, int mode)
 
     return res;
 }
-#endif /* _DEBUG */
+#endif /* Py_DEBUG */
 
 #if defined(MS_WINDOWS_DESKTOP) || defined(MS_WINDOWS_APP) || defined(MS_WINDOWS_SYSTEM)
 
@@ -604,7 +604,7 @@ exec_module(PyObject* m)
     INSERTINT(m, "SEM_NOGPFAULTERRORBOX", SEM_NOGPFAULTERRORBOX);
     INSERTINT(m, "SEM_NOOPENFILEERRORBOX", SEM_NOOPENFILEERRORBOX);
 #endif
-#ifdef _DEBUG
+#ifdef Py_DEBUG
     INSERTINT(m, "CRT_WARN", _CRT_WARN);
     INSERTINT(m, "CRT_ERROR", _CRT_ERROR);
     INSERTINT(m, "CRT_ASSERT", _CRT_ASSERT);
diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index 9e70303868e5de..dae2a22c3ec49c 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -94,6 +94,11 @@ WIN32 is still required for the locale module.
 #endif
 #endif /* Py_BUILD_CORE || Py_BUILD_CORE_BUILTIN || Py_BUILD_CORE_MODULE */
 
+/* _DEBUG implies Py_DEBUG */
+#ifdef _DEBUG
+#  define Py_DEBUG 1
+#endif
+
 /* Define to 1 if you want to disable the GIL */
 /* Uncomment the definition for free-threaded builds, or define it manually
  * when compiling extension modules. Note that we test with #ifdef, so
@@ -319,21 +324,21 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
                         This is relevant when using build-system generator (e.g CMake) where
                         the linking is explicitly handled */
 #                       if defined(Py_GIL_DISABLED)
-#                       if defined(_DEBUG)
+#                       if defined(Py_DEBUG)
 #                               pragma comment(lib,"python314t_d.lib")
 #                       elif defined(Py_LIMITED_API)
 #                               pragma comment(lib,"python3t.lib")
 #                       else
 #                               pragma comment(lib,"python314t.lib")
-#                       endif /* _DEBUG */
+#                       endif /* Py_DEBUG */
 #                       else /* Py_GIL_DISABLED */
-#                       if defined(_DEBUG)
+#                       if defined(Py_DEBUG)
 #                               pragma comment(lib,"python314_d.lib")
 #                       elif defined(Py_LIMITED_API)
 #                               pragma comment(lib,"python3.lib")
 #                       else
 #                               pragma comment(lib,"python314.lib")
-#                       endif /* _DEBUG */
+#                       endif /* Py_DEBUG */
 #                       endif /* Py_GIL_DISABLED */
 #               endif /* _MSC_VER && !Py_NO_LINK_LIB */
 #       endif /* Py_BUILD_CORE */
@@ -376,11 +381,6 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
 #       define ALIGNOF_MAX_ALIGN_T 8
 #endif
 
-#ifdef _DEBUG
-#       define Py_DEBUG
-#endif
-
-
 #ifdef MS_WIN32
 
 #define SIZEOF_SHORT 2
diff --git a/PC/python_uwp.cpp b/PC/python_uwp.cpp
index b9c408a580c999..8cdb8d722cdb9a 100644
--- a/PC/python_uwp.cpp
+++ b/PC/python_uwp.cpp
@@ -19,13 +19,13 @@
 #include <winrt\Windows.Storage.h>
 
 #ifdef PYTHONW
-#ifdef _DEBUG
+#ifdef Py_DEBUG
 const wchar_t *PROGNAME = L"pythonw_d.exe";
 #else
 const wchar_t *PROGNAME = L"pythonw.exe";
 #endif
 #else
-#ifdef _DEBUG
+#ifdef Py_DEBUG
 const wchar_t *PROGNAME = L"python_d.exe";
 #else
 const wchar_t *PROGNAME = L"python.exe";
diff --git a/PC/python_ver_rc.h b/PC/python_ver_rc.h
index ee867fe41224c3..bb98144cd03f15 100644
--- a/PC/python_ver_rc.h
+++ b/PC/python_ver_rc.h
@@ -10,7 +10,7 @@
 #define MS_WINDOWS
 #include "modsupport.h"
 #include "patchlevel.h"
-#ifdef _DEBUG
+#ifdef Py_DEBUG
 #   define PYTHON_DEBUG_EXT "_d"
 #else
 #   define PYTHON_DEBUG_EXT
diff --git a/Python/dynload_win.c b/Python/dynload_win.c
index 6324063401e51f..de9b0a77817a63 100644
--- a/Python/dynload_win.c
+++ b/Python/dynload_win.c
@@ -108,7 +108,7 @@ static char *GetPythonImport (HINSTANCE hModule)
                 char *pch;
 
                 /* Don't claim that python3.dll is a Python DLL. */
-#ifdef _DEBUG
+#ifdef Py_DEBUG
                 if (strcmp(import_name, "python3_d.dll") == 0) {
 #else
                 if (strcmp(import_name, "python3.dll") == 0) {
@@ -120,7 +120,7 @@ static char *GetPythonImport (HINSTANCE hModule)
                 /* Ensure python prefix is followed only
                    by numbers to the end of the basename */
                 pch = import_name + 6;
-#ifdef _DEBUG
+#ifdef Py_DEBUG
                 while (*pch && pch[0] != '_' && pch[1] != 'd' && pch[2] != '.') {
 #else
                 while (*pch && *pch != '.') {
@@ -300,7 +300,7 @@ dl_funcptr _PyImport_FindSharedFuncptrWindows(const char *prefix,
             char buffer[256];
 
             PyOS_snprintf(buffer, sizeof(buffer),
-#ifdef _DEBUG
+#ifdef Py_DEBUG
                           "python%d%d_d.dll",
 #else
                           "python%d%d.dll",
diff --git a/Python/marshal.c b/Python/marshal.c
index b39c1a5b1ade50..afbef6ee6796d9 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -38,7 +38,7 @@ module marshal
  * On Windows PGO builds, the r_object function overallocates its stack and
  * can cause a stack overflow. We reduce the maximum depth for all Windows
  * releases to protect against this.
- * #if defined(MS_WINDOWS) && defined(_DEBUG)
+ * #if defined(MS_WINDOWS) && defined(Py_DEBUG)
  */
 #if defined(MS_WINDOWS)
 #  define MAX_MARSHAL_STACK_DEPTH 1000
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 934614e73b56f9..59c261333103e6 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -3134,7 +3134,7 @@ static inline void _Py_NO_RETURN
 fatal_error_exit(int status)
 {
     if (status < 0) {
-#if defined(MS_WINDOWS) && defined(_DEBUG)
+#if defined(MS_WINDOWS) && defined(Py_DEBUG)
         DebugBreak();
 #endif
         abort();