diff --git a/changelog/13235.bugfix.rst b/changelog/13235.bugfix.rst
new file mode 100644
index 00000000000..88ef80a8e2d
--- /dev/null
+++ b/changelog/13235.bugfix.rst
@@ -0,0 +1,5 @@
+Fixed :func:`pytest.mark.parametrize` with an empty ``argvalues`` list and a
+callable ``ids`` parameter leaking the internal ``NOTSET`` string as the test
+ID (e.g. ``test_foo[NOTSET]``). The callable is no longer invoked for the
+placeholder parameterset, and the generated ID now follows the standard
+auto-naming convention (e.g. ``test_foo[x0]``).
diff --git a/src/_pytest/mark/structures.py b/src/_pytest/mark/structures.py
index 35fd24f8f96..6a8f3cd84ed 100644
--- a/src/_pytest/mark/structures.py
+++ b/src/_pytest/mark/structures.py
@@ -237,9 +237,7 @@ def _for_parametrize(
             # parameter set with NOTSET values, with the "empty parameter set" mark applied to it.
             mark = get_empty_parameterset_mark(config, argnames, func)
             parameters.append(
-                ParameterSet(
-                    values=(NOTSET,) * len(argnames), marks=[mark], id="NOTSET"
-                )
+                ParameterSet(values=(NOTSET,) * len(argnames), marks=[mark], id=None)
             )
         return argnames, parameters
 
diff --git a/src/_pytest/python.py b/src/_pytest/python.py
index ad5a2c6a59b..b8e152a2131 100644
--- a/src/_pytest/python.py
+++ b/src/_pytest/python.py
@@ -1013,6 +1013,8 @@ def _idval_from_function(self, val: object, argname: str, idx: int) -> str | Non
         user-provided id callable, if given."""
         if self.idfn is None:
             return None
+        if val is NOTSET:
+            return None
         try:
             id = self.idfn(val)
         except Exception as e:
diff --git a/testing/python/metafunc.py b/testing/python/metafunc.py
index 026589d65f5..fa91e433d39 100644
--- a/testing/python/metafunc.py
+++ b/testing/python/metafunc.py
@@ -1475,6 +1475,21 @@ def test_temp(temp):
         result = pytester.runpytest()
         result.stdout.fnmatch_lines(["* 1 skipped *"])
 
+    def test_parametrize_empty_argvalues_callable_ids(self, pytester: Pytester) -> None:
+        """Callable ids with empty argvalues must not crash or leak 'NOTSET' (#13235)."""
+        pytester.makepyfile(
+            """
+            import pytest
+
+            @pytest.mark.parametrize("x", [], ids=lambda x: x.id)
+            def test_foo(x):
+                pass
+        """
+        )
+        result = pytester.runpytest("-v")
+        result.stdout.no_fnmatch_line("*NOTSET*")
+        result.stdout.fnmatch_lines(["* 1 skipped *"])
+
     def test_parametrized_ids_invalid_type(self, pytester: Pytester) -> None:
         """Test error with non-strings/non-ints, without generator (#1857)."""
         pytester.makepyfile(