The 26-year-old played has played three Tests, the last of which came at Durham in this summer's Ashes series.
He was then sent home with a suspected stress fracture of the back and although the problem was not as bad as initially feared he has yet to play competitively since.
Bird, who has 109 first-class wickets at an average of 20.77, will be available for 10 LV= County Championship matches and seven Friends Life T20 fixtures.
Northamptonshire had previously announced a raft of contract extensions with senior players and also signed Maurice Chambers and Graeme White to bolster the squad.
Chief executive David Smith said: "The signing of Bird alongside Maurice and Graeme will see the completion of the club's recruitment policy for next season."
- Sports & Recreation
- Maurice Chambers