The clip shows the British public enjoying the holiday, and features cameos from Pippa Middleton and a topless Prince Harry.
EA has previously released videos to celebrate other national events in the UK, including last year's Royal Wedding.
The next The Sims 3 expansion pack, Katy Perry's Sweet Treats, will be available on PC and Mac in June.
> Cassetteboy vs the Diamond Queen - watch video
Screenshots: View images of the Katy Perry's Sweet Treats expansion below: