The 2004 USC Trojans football team represented the University of Southern California in the 2004 NCAA Division I-A football season. Although now vacated for breaking NCAA rules, the team won the 2004 BCS National Championship by winning the 2005 Orange Bowl, that year's BCS National Championship Game. The team also won the AP title for the second year in a row. It was the Trojans' first undisputed national championship since 1972. The team was coached by Pete Carroll in his fourth year with the Trojans, and played their home games in the Los Angeles Memorial Coliseum.
Quarterback Matt Leinart won the Heisman Trophy as the most outstanding collegiate football player in the U.S. His teammate, running back Reggie Bush, finished fifth in Heisman voting, winning the following year. Both were named co-winners of the Pac-10 Offensive Player of the Year. The team captains were Shaun Cody, Matt Grootegoed and Matt Leinart.
Because of the controversy that ended the 2003 NCAA Division I-A football season with a split national title between LSU and USC, the motto for the Trojans' 2004 season became "Leave No Doubt." Ironically, the changes made to the BCS due to the 2003 season did not resolve issues with multiple undefeated teams, as Auburn and Utah finished undefeated, yet they did not get to play USC or any other team for the title.
On June 10, 2010, USC was forced to vacate its two final wins from the 2004 season (December 2004 against UCLA and the BCS championship game), as well as all wins from the 2005 season, following an NCAA investigation into possible violations by the Trojans' football and men's basketball programs. Since the vacated games included the Trojans' Orange Bowl win, the Trojans were later stripped of the 2004 BCS title in June 2011. However, the Associated Press still recognizes USC as 2004 AP title winner.