Bethesda announced the news via Twitter, remarking at the popularity of the PC downloads: "Skyrim Steam Workshop downloads are over 13.6 million. PC mods FTW."
The Elder Scrolls V: Skyrim Creation Kit and Skyrim Workshop were made available to users in February.
Skyrim's Creation Kit grants players access to the toolset Bethesda used to develop the game, enabling the creation of user-generated content. The Workshop is a listing of the latest mods, complete with ratings and automatic downloads.
To celebrate its launch, Valve released an official mod, which sees Space Core from Portal 2 follow users around the open-world role-playing game.
Elder Scrolls V: Skyrim was announced as the fastest-selling PC game on digital distribution service Steam.
> Read our review of 'Elder Scrolls V: Skyrim'
Watch a video outlining Skyrim's Creation Kit and Skyrim Workshop below: