LOS ANGELES -- Longtime TCU coach Gary Patterson has agreed to become Lincoln Riley's defensive coordinator at USC.

USC announced the deal Friday with Patterson, who was part of the College Football Hall of Fame's 2026 class announced this month, recognizing his four-decade coaching career highlighted by 22 seasons as the groundbreaking head coach of the Horned Frogs. He is one of just four coaches to win The Associated Press' Coach of the Year award twice.

"As a Hall of Fame coach who is one of the game's most highly regarded defensive minds, he brings a wealth of success and experience to our program," Riley said in a statement. "His impact will be immediate, elevating our defense and strengthening the culture we've built."

Patterson went 181-79 at TCU with 10 bowl victories, 11 seasons of double-digit wins and two unbeaten regular seasons. The Horned Frogs won or shared titles in three different conferences during his tenure, and they earned a historic Rose Bowl victory over Wisconsin on Jan. 1, 2011, to complete a 13-0 campaign with an eventual No. 2 final ranking behind national champion Auburn.

TCU finished inside the AP top 10 in six seasons under Patterson, but he mutually agreed to part ways with the school in October 2021 after the Frogs got out to a 3-5 start following three straight mediocre seasons.

Patterson, who turns 66 next month, replaces D'Anton Lynn at USC. Lynn left the Trojans for his alma mater, Penn State, shortly before USC's heartbreaking loss to TCU in the Alamo Bowl last month.

Lynn had spent the past two seasons at USC, and he restored competence to a unit that was mostly awful during Riley's first two seasons with coordinator Alex Grinch, who followed Riley from Oklahoma to Los Angeles.

Patterson has always been a defense-minded coach, but he hasn't been a coordinator since his first three seasons on staff at TCU under Dennis Franchione, moving up to head coach after Franchione left following the 2000 regular season.

Following his surprising departure from TCU, Patterson was an on-field analyst at Texas for former USC head coach Steve Sarkisian in 2022. Patterson didn't coach in 2023, and he briefly served as a consultant at Baylor in 2024 before taking last year off as well.

Patterson could play a major role in determining Riley's future at USC. The high-priced coach hasn't produced the level of success expected with the Trojans, who haven't even contended for a College Football Playoff spot or a conference title in the three years since Caleb Williams' Heisman Trophy-winning performance in Riley's debut season in 2022.

USC showed progress last season, improving to 9-4 with three road losses to ranked teams. The Trojans are returning for Riley's fifth season in the fall with a talent-stacked roster from an elite recruiting class and another dip into the transfer portal.