diff --git a/Doc/c-api/sys.rst b/Doc/c-api/sys.rst
index c688afdca8231d..d51e66d45d22b3 100644
--- a/Doc/c-api/sys.rst
+++ b/Doc/c-api/sys.rst
@@ -216,6 +216,22 @@ Operating System Utilities
       The function now uses the UTF-8 encoding on Windows if
       :c:member:`PyPreConfig.legacy_windows_fs_encoding` is zero.
 
+.. c:function:: FILE* Py_fopen(PyObject *path, const char *mode)
+
+   Similar to the :c:func:`!fopen` function, but *path* is a Python object and
+   an exception is set on error.
+
+   *path* must be a :class:`str` object or a :class:`bytes` object.
+
+   On success, return the new file object.
+   On error, set an exception and return ``NULL``.
+
+   The file descriptor is created non-inheritable (:pep:`446`).
+
+   The caller must hold the GIL.
+
+   .. versionadded:: next
+
 
 .. _systemfunctions:
 
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index b71d31f9742fe0..2ce1bcdad75fbc 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -1034,6 +1034,11 @@ New features
 * Add :c:func:`PyUnstable_Object_EnableDeferredRefcount` for enabling
   deferred reference counting, as outlined in :pep:`703`.
 
+* Add :c:func:`Py_fopen` function to open a file. Similar to the
+  :c:func:`!fopen` function, but the *path* parameter is a Python object and an
+  exception is set on error.
+  (Contributed by Victor Stinner in :gh:`127350`.)
+
 Porting to Python 3.14
 ----------------------
 
diff --git a/Include/cpython/fileutils.h b/Include/cpython/fileutils.h
index b386ad107bde1f..3a2bfae1add88e 100644
--- a/Include/cpython/fileutils.h
+++ b/Include/cpython/fileutils.h
@@ -2,7 +2,6 @@
 #  error "this header file must not be included directly"
 #endif
 
-// Used by _testcapi which must not use the internal C API
-PyAPI_FUNC(FILE*) _Py_fopen_obj(
+PyAPI_FUNC(FILE*) Py_fopen(
     PyObject *path,
     const char *mode);
diff --git a/Lib/test/test_capi/test_file.py b/Lib/test/test_capi/test_file.py
new file mode 100644
index 00000000000000..68e63ad2a3e490
--- /dev/null
+++ b/Lib/test/test_capi/test_file.py
@@ -0,0 +1,23 @@
+import os
+import unittest
+from test.support import import_helper
+
+_testcapi = import_helper.import_module('_testcapi')
+
+
+class CAPIFileTest(unittest.TestCase):
+    def test_py_fopen(self):
+        for filename in (__file__, os.fsencode(__file__)):
+            with self.subTest(filename=filename):
+                content = _testcapi.py_fopen(filename, "rb")
+                with open(filename, "rb") as fp:
+                    self.assertEqual(fp.read(256), content)
+
+        for invalid_type in (123, object()):
+            with self.subTest(filename=invalid_type):
+                with self.assertRaises(TypeError):
+                    _testcapi.py_fopen(invalid_type, "r")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index 59f37b3f9a7575..122c1e7882864f 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -1325,8 +1325,7 @@ def test_load_verify_cadata(self):
     def test_load_dh_params(self):
         ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
         ctx.load_dh_params(DHFILE)
-        if os.name != 'nt':
-            ctx.load_dh_params(BYTES_DHFILE)
+        ctx.load_dh_params(BYTES_DHFILE)
         self.assertRaises(TypeError, ctx.load_dh_params)
         self.assertRaises(TypeError, ctx.load_dh_params, None)
         with self.assertRaises(FileNotFoundError) as cm:
diff --git a/Misc/NEWS.d/next/C_API/2024-12-11-13-01-26.gh-issue-127350.uEBZZ4.rst b/Misc/NEWS.d/next/C_API/2024-12-11-13-01-26.gh-issue-127350.uEBZZ4.rst
new file mode 100644
index 00000000000000..e3a914188ca680
--- /dev/null
+++ b/Misc/NEWS.d/next/C_API/2024-12-11-13-01-26.gh-issue-127350.uEBZZ4.rst
@@ -0,0 +1,3 @@
+Add :c:func:`Py_fopen` function to open a file. Similar to the :c:func:`!fopen`
+function, but the *path* parameter is a Python object and an exception is set
+on error. Patch by Victor Stinner.
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index e7df132869fee6..accc9b7a3ac481 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -4377,7 +4377,7 @@ _ssl__SSLContext_load_dh_params_impl(PySSLContext *self, PyObject *filepath)
     FILE *f;
     DH *dh;
 
-    f = _Py_fopen_obj(filepath, "rb");
+    f = Py_fopen(filepath, "rb");
     if (f == NULL)
         return NULL;
 
diff --git a/Modules/_ssl/debughelpers.c b/Modules/_ssl/debughelpers.c
index 9c87f8b4d21e68..318c045a0eec3c 100644
--- a/Modules/_ssl/debughelpers.c
+++ b/Modules/_ssl/debughelpers.c
@@ -180,8 +180,8 @@ _PySSLContext_set_keylog_filename(PySSLContext *self, PyObject *arg, void *c) {
         return 0;
     }
 
-    /* _Py_fopen_obj() also checks that arg is of proper type. */
-    fp = _Py_fopen_obj(arg, "a" PY_STDIOTEXTMODE);
+    /* Py_fopen() also checks that arg is of proper type. */
+    fp = Py_fopen(arg, "a" PY_STDIOTEXTMODE);
     if (fp == NULL)
         return -1;
 
diff --git a/Modules/_testcapi/clinic/file.c.h b/Modules/_testcapi/clinic/file.c.h
new file mode 100644
index 00000000000000..9856b6161cdfa0
--- /dev/null
+++ b/Modules/_testcapi/clinic/file.c.h
@@ -0,0 +1,48 @@
+/*[clinic input]
+preserve
+[clinic start generated code]*/
+
+#include "pycore_modsupport.h"    // _PyArg_CheckPositional()
+
+PyDoc_STRVAR(_testcapi_py_fopen__doc__,
+"py_fopen($module, path, mode, /)\n"
+"--\n"
+"\n"
+"Call Py_fopen() and return fread(256).");
+
+#define _TESTCAPI_PY_FOPEN_METHODDEF    \
+    {"py_fopen", _PyCFunction_CAST(_testcapi_py_fopen), METH_FASTCALL, _testcapi_py_fopen__doc__},
+
+static PyObject *
+_testcapi_py_fopen_impl(PyObject *module, PyObject *path, const char *mode);
+
+static PyObject *
+_testcapi_py_fopen(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *return_value = NULL;
+    PyObject *path;
+    const char *mode;
+
+    if (!_PyArg_CheckPositional("py_fopen", nargs, 2, 2)) {
+        goto exit;
+    }
+    path = args[0];
+    if (!PyUnicode_Check(args[1])) {
+        _PyArg_BadArgument("py_fopen", "argument 2", "str", args[1]);
+        goto exit;
+    }
+    Py_ssize_t mode_length;
+    mode = PyUnicode_AsUTF8AndSize(args[1], &mode_length);
+    if (mode == NULL) {
+        goto exit;
+    }
+    if (strlen(mode) != (size_t)mode_length) {
+        PyErr_SetString(PyExc_ValueError, "embedded null character");
+        goto exit;
+    }
+    return_value = _testcapi_py_fopen_impl(module, path, mode);
+
+exit:
+    return return_value;
+}
+/*[clinic end generated code: output=968f4f4a620f13cf input=a9049054013a1b77]*/
diff --git a/Modules/_testcapi/file.c b/Modules/_testcapi/file.c
index 634563f6ea12cb..b163ec0efcb78b 100644
--- a/Modules/_testcapi/file.c
+++ b/Modules/_testcapi/file.c
@@ -1,8 +1,43 @@
+// clinic/file.c.h uses internal pycore_modsupport.h API
+#define PYTESTCAPI_NEED_INTERNAL_API
+
 #include "parts.h"
 #include "util.h"
+#include "clinic/file.c.h"
+
+/*[clinic input]
+module _testcapi
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=6361033e795369fc]*/
+
+/*[clinic input]
+_testcapi.py_fopen
+
+    path: object
+    mode: str
+    /
+
+Call Py_fopen() and return fread(256).
+[clinic start generated code]*/
 
+static PyObject *
+_testcapi_py_fopen_impl(PyObject *module, PyObject *path, const char *mode)
+/*[clinic end generated code: output=5a900af000f759de input=0878c2f9333abd60]*/
+{
+    FILE *fp = Py_fopen(path, mode);
+    if (fp == NULL) {
+        return NULL;
+    }
+
+    char buffer[256];
+    size_t size = fread(buffer, 1, Py_ARRAY_LENGTH(buffer), fp);
+    fclose(fp);
+
+    return PyBytes_FromStringAndSize(buffer, size);
+}
 
 static PyMethodDef test_methods[] = {
+    _TESTCAPI_PY_FOPEN_METHODDEF
     {NULL},
 };
 
diff --git a/Modules/_testcapi/object.c b/Modules/_testcapi/object.c
index 3af5429ef00985..841410c52b3ce2 100644
--- a/Modules/_testcapi/object.c
+++ b/Modules/_testcapi/object.c
@@ -15,7 +15,7 @@ call_pyobject_print(PyObject *self, PyObject * args)
         return NULL;
     }
 
-    fp = _Py_fopen_obj(filename, "w+");
+    fp = Py_fopen(filename, "w+");
 
     if (Py_IsTrue(print_raw)) {
         flags = Py_PRINT_RAW;
@@ -41,7 +41,7 @@ pyobject_print_null(PyObject *self, PyObject *args)
         return NULL;
     }
 
-    fp = _Py_fopen_obj(filename, "w+");
+    fp = Py_fopen(filename, "w+");
 
     if (PyObject_Print(NULL, fp, 0) < 0) {
         fclose(fp);
@@ -72,7 +72,7 @@ pyobject_print_noref_object(PyObject *self, PyObject *args)
         return NULL;
     }
 
-    fp = _Py_fopen_obj(filename, "w+");
+    fp = Py_fopen(filename, "w+");
 
     if (PyObject_Print(test_string, fp, 0) < 0){
         fclose(fp);
@@ -103,7 +103,7 @@ pyobject_print_os_error(PyObject *self, PyObject *args)
     }
 
     // open file in read mode to induce OSError
-    fp = _Py_fopen_obj(filename, "r");
+    fp = Py_fopen(filename, "r");
 
     if (PyObject_Print(test_string, fp, 0) < 0) {
         fclose(fp);
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 8d86b535effb9a..994785191c4bb5 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1744,7 +1744,7 @@ pymarshal_write_long_to_file(PyObject* self, PyObject *args)
                           &value, &filename, &version))
         return NULL;
 
-    fp = _Py_fopen_obj(filename, "wb");
+    fp = Py_fopen(filename, "wb");
     if (fp == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
@@ -1769,7 +1769,7 @@ pymarshal_write_object_to_file(PyObject* self, PyObject *args)
                           &obj, &filename, &version))
         return NULL;
 
-    fp = _Py_fopen_obj(filename, "wb");
+    fp = Py_fopen(filename, "wb");
     if (fp == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
@@ -1793,7 +1793,7 @@ pymarshal_read_short_from_file(PyObject* self, PyObject *args)
     if (!PyArg_ParseTuple(args, "O:pymarshal_read_short_from_file", &filename))
         return NULL;
 
-    fp = _Py_fopen_obj(filename, "rb");
+    fp = Py_fopen(filename, "rb");
     if (fp == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
@@ -1818,7 +1818,7 @@ pymarshal_read_long_from_file(PyObject* self, PyObject *args)
     if (!PyArg_ParseTuple(args, "O:pymarshal_read_long_from_file", &filename))
         return NULL;
 
-    fp = _Py_fopen_obj(filename, "rb");
+    fp = Py_fopen(filename, "rb");
     if (fp == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
@@ -1840,7 +1840,7 @@ pymarshal_read_last_object_from_file(PyObject* self, PyObject *args)
     if (!PyArg_ParseTuple(args, "O:pymarshal_read_last_object_from_file", &filename))
         return NULL;
 
-    FILE *fp = _Py_fopen_obj(filename, "rb");
+    FILE *fp = Py_fopen(filename, "rb");
     if (fp == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
@@ -1863,7 +1863,7 @@ pymarshal_read_object_from_file(PyObject* self, PyObject *args)
     if (!PyArg_ParseTuple(args, "O:pymarshal_read_object_from_file", &filename))
         return NULL;
 
-    FILE *fp = _Py_fopen_obj(filename, "rb");
+    FILE *fp = Py_fopen(filename, "rb");
     if (fp == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
diff --git a/Modules/main.c b/Modules/main.c
index 15ea49a1bad19e..29b944aab84bec 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -370,7 +370,7 @@ pymain_run_file_obj(PyObject *program_name, PyObject *filename,
         return pymain_exit_err_print();
     }
 
-    FILE *fp = _Py_fopen_obj(filename, "rb");
+    FILE *fp = Py_fopen(filename, "rb");
     if (fp == NULL) {
         // Ignore the OSError
         PyErr_Clear();
@@ -464,7 +464,7 @@ pymain_run_startup(PyConfig *config, int *exitcode)
         goto error;
     }
 
-    FILE *fp = _Py_fopen_obj(startup, "r");
+    FILE *fp = Py_fopen(startup, "r");
     if (fp == NULL) {
         int save_errno = errno;
         PyErr_Clear();
diff --git a/Python/errors.c b/Python/errors.c
index 7f3b4aabc432d7..3376012dca4d01 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -1972,7 +1972,7 @@ _PyErr_ProgramDecodedTextObject(PyObject *filename, int lineno, const char* enco
         return NULL;
     }
 
-    FILE *fp = _Py_fopen_obj(filename, "r" PY_STDIOTEXTMODE);
+    FILE *fp = Py_fopen(filename, "r" PY_STDIOTEXTMODE);
     if (fp == NULL) {
         PyErr_Clear();
         return NULL;
diff --git a/Python/fileutils.c b/Python/fileutils.c
index 9529b14d377c60..c039fdc8f3309e 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -1748,8 +1748,10 @@ _Py_wfopen(const wchar_t *path, const wchar_t *mode)
 }
 
 
-/* Open a file. Call _wfopen() on Windows, or encode the path to the filesystem
-   encoding and call fopen() otherwise.
+/* Open a file.
+
+   On Windows, if 'path' is a Unicode string, call _wfopen(). Otherwise, encode
+   the path to the filesystem encoding and call fopen().
 
    Return the new file object on success. Raise an exception and return NULL
    on error.
@@ -1762,72 +1764,64 @@ _Py_wfopen(const wchar_t *path, const wchar_t *mode)
    Release the GIL to call _wfopen() or fopen(). The caller must hold
    the GIL. */
 FILE*
-_Py_fopen_obj(PyObject *path, const char *mode)
+Py_fopen(PyObject *path, const char *mode)
 {
-    FILE *f;
-    int async_err = 0;
-#ifdef MS_WINDOWS
-    wchar_t wmode[10];
-    int usize;
-
     assert(PyGILState_Check());
 
     if (PySys_Audit("open", "Osi", path, mode, 0) < 0) {
         return NULL;
     }
-    if (!PyUnicode_Check(path)) {
-        PyErr_Format(PyExc_TypeError,
-                     "str file path expected under Windows, got %R",
-                     Py_TYPE(path));
-        return NULL;
-    }
 
-    wchar_t *wpath = PyUnicode_AsWideCharString(path, NULL);
-    if (wpath == NULL)
-        return NULL;
+    FILE *f;
+    int async_err = 0;
+    int saved_errno;
+#ifdef MS_WINDOWS
+    if (PyUnicode_Check(path)) {
+        wchar_t *wpath = PyUnicode_AsWideCharString(path, NULL);
+        if (wpath == NULL) {
+            return NULL;
+        }
 
-    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1,
-                                wmode, Py_ARRAY_LENGTH(wmode));
-    if (usize == 0) {
-        PyErr_SetFromWindowsErr(0);
+        wchar_t wmode[10];
+        int usize = MultiByteToWideChar(CP_ACP, 0, mode, -1,
+                                        wmode, Py_ARRAY_LENGTH(wmode));
+        if (usize == 0) {
+            PyErr_SetFromWindowsErr(0);
+            PyMem_Free(wpath);
+            return NULL;
+        }
+
+        do {
+            Py_BEGIN_ALLOW_THREADS
+            f = _wfopen(wpath, wmode);
+            Py_END_ALLOW_THREADS
+        } while (f == NULL
+                 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+        saved_errno = errno;
         PyMem_Free(wpath);
-        return NULL;
     }
+    else
+#endif
+    {
+        PyObject *bytes;
+        if (!PyUnicode_FSConverter(path, &bytes)) {
+            return NULL;
+        }
+        const char *path_bytes = PyBytes_AS_STRING(bytes);
 
-    do {
-        Py_BEGIN_ALLOW_THREADS
-        f = _wfopen(wpath, wmode);
-        Py_END_ALLOW_THREADS
-    } while (f == NULL
-             && errno == EINTR && !(async_err = PyErr_CheckSignals()));
-    int saved_errno = errno;
-    PyMem_Free(wpath);
-#else
-    PyObject *bytes;
-    const char *path_bytes;
-
-    assert(PyGILState_Check());
-
-    if (!PyUnicode_FSConverter(path, &bytes))
-        return NULL;
-    path_bytes = PyBytes_AS_STRING(bytes);
-
-    if (PySys_Audit("open", "Osi", path, mode, 0) < 0) {
+        do {
+            Py_BEGIN_ALLOW_THREADS
+            f = fopen(path_bytes, mode);
+            Py_END_ALLOW_THREADS
+        } while (f == NULL
+                 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+        saved_errno = errno;
         Py_DECREF(bytes);
-        return NULL;
     }
 
-    do {
-        Py_BEGIN_ALLOW_THREADS
-        f = fopen(path_bytes, mode);
-        Py_END_ALLOW_THREADS
-    } while (f == NULL
-             && errno == EINTR && !(async_err = PyErr_CheckSignals()));
-    int saved_errno = errno;
-    Py_DECREF(bytes);
-#endif
-    if (async_err)
+    if (async_err) {
         return NULL;
+    }
 
     if (f == NULL) {
         errno = saved_errno;
diff --git a/Python/import.c b/Python/import.c
index b3c384c27718ce..9566b596703884 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -4687,7 +4687,7 @@ _imp_create_dynamic_impl(PyObject *module, PyObject *spec, PyObject *file)
      * code relies on fp still being open. */
     FILE *fp;
     if (file != NULL) {
-        fp = _Py_fopen_obj(info.filename, "r");
+        fp = Py_fopen(info.filename, "r");
         if (fp == NULL) {
             goto finally;
         }
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 8b57018321c070..8b8a9e72a9ac61 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -467,7 +467,7 @@ _PyRun_SimpleFileObject(FILE *fp, PyObject *filename, int closeit,
             fclose(fp);
         }
 
-        pyc_fp = _Py_fopen_obj(filename, "rb");
+        pyc_fp = Py_fopen(filename, "rb");
         if (pyc_fp == NULL) {
             fprintf(stderr, "python: Can't reopen .pyc file\n");
             goto done;