Ty Dieffenbach (born June 8, 2005) is an American college football quarterback for the UCLA Bruins. He previously played for the Pittsburgh Panthers and Cal Poly Mustangs.
Contents
Early life
Dieffenbach attended Agoura High School in Agoura Hills, California. After beginning his career as a wide receiver, he moved to quarterback as a sophomore. Despite never playing the position before, he had impressed head coach Dustin Croick with his passing in practice, and the team needed a quarterback. As a junior, Dieffenbach threw for 2,669 yards and a school-record 34 touchdowns. He committed to the University of Pittsburgh to play college football.
College career
Dieffenbach spent two seasons at Pittsburgh with the Panthers but did not appear in a game. Following the conclusion of the 2024 season, he entered the transfer portal. Pitt had wanted him to move to tight end, but his desire was to remain a quarterback. Dieffenbach transferred to California Polytechnic State University, San Luis Obispo, to play for the Cal Poly Mustangs. In his collegiate debut and first career start, in the 2025 season opener against San Diego, he completed 18 passes for 263 yards and two touchdowns while adding a rushing touchdown. Dieffenbach's performance earned him Big Sky Offensive Player of the Week honors. He appeared in 11 games, making nine starts, and recorded 1,305 passing yards, nine touchdowns, and nine interceptions while rushing for 321 yards and four touchdowns. Dieffenbach entered the transfer portal for the second time following the end of the season.
Dieffenbach announced in January 2026 that he would transfer to the University of California, Los Angeles, to play for the UCLA Bruins. He entered the season as the third-string quarterback behind brothers Nico and Madden Iamaleava. After Nico was injured against No. 13 Oregon, Dieffenbach took over at quarterback, throwing for 43 yards and a touchdown to lead the Bruins to a 17–15 upset victory. With Nico out indefinitely, UCLA head coach Bob Chesney named Dieffenbach the starter for the following game against Wisconsin. In his first start for the Bruins as well as in a Football Bowl Subdivision game, he completed 22 of 33 passes for 264 yards in a 17–7 win over the Badgers.