Leinart played college football for the University of Southern California (USC). In 2004, he was named that year's winner of the Heisman Trophy, and led the USC Trojans to the BCS national championship. After graduation, Leinart's number 11 jersey was retired by USC. At the end of his college career, he was won the Archie Griffin Award twice, named two time First Team All American, won quarterback of the year twice, won the Heisman Trophy, led USC to back-to-back National Championships, and won the Manning Award, the Johnny Unitas Award, and the Walter Camp Award. 

The left-handed passing Leinart was selected tenth overall in the 2006 NFL draft by the Arizona Cardinals. After four years in Arizona, Leinart signed a one year contract with the Houston Texans. One year later, he signed to play with the Oakland Raiders in 2012.