The Trojans will become eligible to compete in a bowl game next season after suffering through two years of NCAA-imposed sanctions. With Barkley as quarterback, they will likely be among the top teams in the national rankings at the start of the 2012 campaign.
Barkley threw for 39 touchdowns this season and had a 69.1 completion percentage, both single-season USC records.
He set single-game school records this season by throwing for 468 yards against Arizona, completing 35 passes against UCLA and connecting on six touchdown throws against both UCLA and Colorado.
"I know in my heart that I have not yet finished my journey as a Trojans football player," Barkley said at a news conference announcing his decision. "I have firmly decided to forego the NFL Draft in 2012 and finish this exceptional and unique journey that I have had here at USC."
Barkley was sixth in this year's balloting for the Heisman Trophy. He led USC to a 10-2 record, which the Trojans completed with a 50-0 smashing of UCLA. USC, because of its sanctions, was not eligible to take part in the first Pacific-12 Conference title game.