Eager to pursue a career in acting, Jenner left Miami and moved to
Los Angeles after graduating from high school a year early, with just $2,500. While residing in California, he took on many jobs including a waiter, clothing store associate, and parrot salesman while auditioning for acting roles. He continually attended improv classes at
The Groundlings, and eventually did a guest show with that company two years later. By 2011, he was cast in the short films
Wurlitzer and
The Truth In Being Right and the horror film
Cousin Sarah. He also made a guest appearance on
ABC Family's sitcom
Melissa & Joey as Miller Collins. In 2012, he was selected through industry channels to audition as one of 15 contestants on the second season of
The Glee Project, a television
reality show for which the prize was a guaranteed seven-episode arc on the following season of
Glee. He was one of three finalists and ultimately won. After appearing as Ryder Lynn on the fourth season of
Glee, he was later nominated and won the
Teen Choice Award for Choice TV Breakout Star. Jenner, along with co-stars
Jacob Artist,
Becca Tobin,
Alex Newell, and
Melissa Benoist, was promoted to series regular status for the
fifth season. In the summer of 2013, Jenner wrote the screenplay for
Billy Boy. He and Benoist went on
Kickstarter to ask fans to help fund the project's production; as of December 11, 2013, the project has reached its $100,000 goal. Jenner was subsequently cast in the horror film
Within. In late 2015, Jenner was cast in a recurring role as Adam Foster on
Supergirl, playing opposite his then-wife Melissa Benoist, who stars as the series' title character. His first appearance aired on January 25, 2016. In 2016, Jenner starred as Jake Bradford in
Richard Linklater's comedy film
Everybody Wants Some!!, which was released on March 30, and played
Hailee Steinfeld's character's brother in the coming-of-age drama
The Edge of Seventeen. He was in the cast of
Shawn Christensen's drama film
The Vanishing of Sidney Hall, which premiered at the
2017 Sundance Film Festival and was released in 2018. He was in the cast of Bart Layton's crime drama film
American Animals. It premiered at the
2018 Sundance Film Festival and was released in June 2018, by
The Orchard and
MoviePass Ventures. Jenner played Christian de Neuvillette in the
Goodspeed Musical production's
Cyrano at the
Norma Terris Theatre in August and September 2018. Jenner played Sean in
What/If,
Netflix's 2019 anthology neo-noir thriller series. In August 2019, it was announced that Jenner would star in
Richard Linklater's
film adaptation of Merrily We Roll Along, which would be shot over the course of twenty years. Jenner had been set to star alongside
Beanie Feldstein and
Ben Platt. On January 10, 2023, it was announced that Jenner would be replaced in
Merrily We Roll Along by
Paul Mescal. ==Personal life==