Jackson played college football for the University of Southern California and was a 4-year starter for the Trojans starting 51 of 52 games. Philip Rivers (NC State) is the only other player in NCAA history to start 51 games. In 2007 Jackson was an AP All-American second team selection, Collegefootballnews.com All-American third-team, All-Pac-10 first team (making it for the second time after being so honored in 2005), ESPN.com All-Pac-10 first team, Collegefootballnews.com All-Pac-10 first team, and the Rivals.com All-Pac-10 first team. Jackson was on the 2007 Street and Smiths and Phil Steele's preseason All-American first team and on the Ted Hendricks Award and Bednarik Award watch lists.