The decision comes two days after the Trojans, who began the season with conference-title aspirations, were embarrassed in a 42-28 home defeat toStanford.
"As I committed to upon my arrival at USC, during the past two off-seasons we provided every resource necessary for our football program to compete for championships," Bohn said in a statement announcing the dismissal. "The added resources carried significantly increased expectations for our team's performance, and it is already evident that, despite the enhancements, those expectations would not be met without a change in leadership."
Helton was under contract through the 2023 season. His buyout is in the $12 million range, sources told ESPN's Chris Low.
Donte Williams will serve as the interim head coach. Williams joined the USC staff in 2020 as the cornerbacks coach and defensive pass game coordinator and was elevated to associate head coach after last season.A Los Angeles-area native, Williams becomes the first Black head coach in USC football history.
In a tweeted statement, Helton called coaching USC "the opportunity of a lifetime," thanking the school, players and fans.
"To our players, both past and present, I am forever indebted to you for what you have given me," Helton, 49, said in part. "I am so appreciative for all of the hard work that our current staff and student-athletes have put into preparing for this season, and while it will be hard to not be in the fight with you, I am confident that great things lie ahead."
Williams, 39, said he didn't find out about the administration's plans until moments before Helton and Bohn broke the news jointly to the players.
"We have a lot of games left, but the season has started," Williams said. "It's hard to make, I guess, huge changes right now, so my biggest thing is about enhancing everything we do.
"Everyone in this organization needs to do something a little bit [more] than what they were doing before, including myself.''
Helton had been with the program since 2010, when he was hired to be the quarterbacks coach on Lane Kiffin's initial staff. He served as the offensive coordinator under both Kiffin and Steve Sarkisian before being hired as the head coach by then-AD Pat Haden in 2015.
Including two stints as the interim head coach, Helton went 46-24 as the Trojans' coach, including a Rose Bowl win to cap the 2016 season. USC went 1-1 under Helton this season.
"I want to be exceptionally clear: our university and its leadership are committed to winning national championships and restoring USC football to glory," Bohn said. "This decision represents our next step toward that goal in what has been a thoughtful and strategic process to build a comprehensive football organization equivalent to the premier programs in the modern landscape."
A national search for Helton's replacement will take place over the next several months, Bohn said.
Information from The Associated Press was used in this story.
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