The Rams will host the Patriots in late October as the NFL continues to hold a regular season in London next season.
London is the home of Rams owner Stan Kroenke's Arsenal soccer team of the English Premier League.
The 2012 game will be a Rams "home" contest, meaning they will play only seven games next season in the Edward Jones Dome.
It is also believed that this could be a multi-year arrangement with the Rams, not unlike the Bills playing in Toronto.
Rams To Play 'Home Game' In London