The league has confirmed the Jacksonville Jaguars, Atlanta Falcons and Oakland Raiders will all play as the 'home' team - with opponents yet to be named.
The Jaguars are due to play the San Francisco 49ers later this month in the first of four games they have committed to play at Wembley each year until 2016.
Wembley has hosted regular-season games every year since 2007, but this season is the first in which it has staged more than one, with the Minnesota Vikings having beaten the Pittsburgh Steelers 34-27 there last month.
Sell-outs for both the 2013 fixtures have been enough to convince the league London is ready for even more.
NFL commissioner Roger Goodell said: "Our fans in the UK have continued to demonstrate that they love football games and want more.
"Both of this year's games in London sold out quickly. The fan enthusiasm for our sport continues to grow.
"By playing two games in the UK this year, we are creating more fans. We hope that with three games in the London next year we will attract even more people to our game."
The Jaguars are owned by Fulham owner Shahid Khan, and the team is hoping to create a strong foothold with UK fans by returning regularly.
Khan said: "The experience the Jaguars have had already in London has been every bit what we anticipated and more, and this is all before we've even played our first game in Wembley Stadium.
"We made the right decision to commit to playing a home game in London each season through 2016."
Atlanta and Oakland will be venturing outside the United States to play a regular-season game for the first time.
The Raiders were last in London for a pre-season contest against the New Orleans Saints at the old Wembley Stadium in 1990.