Quarterback Leinart, the 10th overall pick in the 2006 draft, was released by the Arizona Cardinals on Saturday after entering their training camp as the starter.
"He's obviously a talented young man to have been the 10th pick in the draft," Texans coach Gary Kubiak told the team's website (http://www.houstontexans.com).
"Those things happen in this business, and it's a chance for him to get a fresh start. We're getting a very smart player who has been productive."
Having led USC to two national championships and a 37-2 record, Leinart made an immediate impact with Arizona in 2006, starting 11 games as a rookie and throwing for 2,547 yards with 11 touchdowns and 12 interceptions.
(Writing by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)