diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-10-18-18-08-36.gh-issue-140301.m-2HxC.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-10-18-18-08-36.gh-issue-140301.m-2HxC.rst
new file mode 100644
index 00000000000000..8b1c81c04ece92
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-10-18-18-08-36.gh-issue-140301.m-2HxC.rst
@@ -0,0 +1 @@
+Fix memory leak of ``PyConfig`` in subinterpreters.
diff --git a/Python/pystate.c b/Python/pystate.c
index 7f365ea50cab7d..06f997fb5ad5be 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -1049,6 +1049,8 @@ PyInterpreterState_Delete(PyInterpreterState *interp)
 
     _PyObject_FiniState(interp);
 
+    PyConfig_Clear(&interp->config);
+
     free_interpreter(interp);
 }