diff --git a/Misc/NEWS.d/next/Windows/2026-06-28-12-37-08.gh-issue-152433.FTMgqF.rst b/Misc/NEWS.d/next/Windows/2026-06-28-12-37-08.gh-issue-152433.FTMgqF.rst
new file mode 100644
index 000000000000000..8a9f2bd38aec796
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2026-06-28-12-37-08.gh-issue-152433.FTMgqF.rst
@@ -0,0 +1 @@
+Implement os.cpu_count() for UWP.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index c52d2e7d5bfbd9f..f5caab35e8798cb 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -15990,7 +15990,9 @@ os_cpu_count_impl(PyObject *module)
 # ifdef MS_WINDOWS_DESKTOP
     ncpu = GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
 # else
-    ncpu = 0;
+    SYSTEM_INFO sysinfo;
+    GetSystemInfo(&sysinfo);
+    ncpu = sysinfo.dwNumberOfProcessors;
 # endif
 
 #elif defined(__hpux)