Financial terms of the deal weren't disclosed.
Lofton, who was an unrestricted free agent, started all 16 games at middle linebacker for the Falcons last season. Jonathan Vilma is the Saints' current starting linebacker and defensive captain, but Lofton also has the ability to play other linebacker spots.
"Curtis is a versatile, hard-working player that has displayed a knack for being around the football, and more importantly, making plays on the ball," Saints general manager Mickey Loomis said Saturday night in a team-issued press release. "He has the ability to play all three linebacker positions, and we feel that he's just entering the prime of his career. We think he can come to New Orleans and fit in well and provide us with a significant contribution to our defense."
The 6-foot, 241-pound Lofton was a second-round draft choice by the Falcons in 2008 and has started 63 of his 64 games.
In four seasons, Lofton has been credited with four sacks, three interceptions, seven forced fumbles, one fumble recovery and 15 passes defended.
The former Oklahoma standout led the Falcons with a career-high 147 tackles last season, to go along with a sack, a forced fumble, a fumble recovery and two interceptions, one of which he ran back 26 yards for a touchdown.
The Saints recently were punished by the NFL for operating a bounty system, and Vilma's name appeared in the report by the league. Commissioner Roger Goodell has said he will deal with player punishment at a later date.
Copyright 2012 by The Associated Press