And first up are the New England Patriots, who are two wins from another Super Bowl title.
The Rams and Patriots meet at Wembley Stadium on Oct. 28, about two months after the closing ceremony of the London Olympics. That will be followed by games at Wembley against undetermined opponents in 2013 and 2014.
The Rams are owned by Stan Kroenke, who is also the majority shareholder in the English soccer club Arsenal. The team will give up home games in St. Louis for the three seasons they are in London.
"We've seen first-hand the increased popularity of the NFL not only in London but throughout Europe," Kroenke said in a statement. "To play a role in that growth over the next three years will be incredible and is a testament to the many good things happening not only in the NFL but also in the St. Louis Rams organization."
This year's contest will be the sixth regular-season game at Wembley. But despite plans to bring a second game to Britain starting next season, the NFL said the Rams-Patriots date would be the only one in 2012.
"This year is a very competitive year for sport in the UK, especially with the Olympics in London," NFLUK managing director Alistair Kirkwood said. "Also, with the Rams having made an unprecedented commitment to playing in the UK for the next three years, we wanted to focus on them as our 'home' team without another game taking place.
"We would like to increase beyond one game per year as soon as possible and the five-year commitment by the owners to playing in the UK allows us to make that decision when we feel it is appropriate."
NFL owners agreed last year to play regular-season games in the UK for the next five seasons. The league said Friday all the games would be played at Wembley. NFL Commissioner Roger Goodell has repeatedly spoken of the possibility of a full-time franchise in the UK one day.
The Rams finished 2-14 this season, tied for the NFL's worst, and have won only 15 games the last five seasons. Last week, the team hired Jeff Fisher as coach to replace the fired Steve Spagnuolo.
The NFL first played at Wembley in 2007, with the New York Giants beating the Miami Dolphins 13-10. Since then, seven other teams have visited Britain, with the Tampa Bay Buccaneers making the trip twice.
The Patriots have already been to London, beating the Bucs 35-7 in 2009. The Bucs returned this season, losing to the Chicago Bears 24-18 in October — the first of the Wembley games that wasn't a sellout.
This season, the Patriots have been one of the best teams in the league. Led by Tom Brady, they will face the Baltimore Ravens on Sunday in the AFC championship with a chance to reach their fifth Super Bowl in the last 11 years.
And Patriots owner Robert Kraft is already looking forward to coming back to London, especially since they again don't have to give up a home game.
"For us in a way it is like, I think, having another home game, we have such a large fan base there," Kraft said. "We have had a group of fans come over from the UK and come here to a game each year and it is a tremendous fan base. Happy we will be able to go over there."
In the NFC championship, the San Francisco 49ers host the New York Giants.