Career
In 2001, Rosenbaum received a Saturn Award for his portrayal of Lex Luthor on Smallville. Continuing in the superhero genre, he played Wally West (a.k.a. the Flash) in the DC Comics animated series Justice League, Static Shock, and Justice League Unlimited, as well as portraying a younger version of Wally West as Kid Flash in Teen Titans. In the third season Justice League Unlimited episode "The Great Brain Robbery", Rosenbaum reprised his role as Lex Luthor when Wally and Lex Luthor temporarily switched bodies. In February 2008, Rosenbaum confirmed that he would be leaving Smallville after the seventh season. After many months of speculation and him first turning down the contract to return, it was announced on February 11, 2011, that Rosenbaum would return to Smallville for the two-hour series finale, which aired on May 13, 2011, with Rosenbaum reprising his role as Lex Luthor.
In 2012, Rosenbaum appeared in Hit and Run, which starred Dax Shepard and Kristen Bell. Rosenbaum portrayed the character Gil, a jealous ex-boyfriend from Annie's (Bell's character) past.
Rosenbaum provided the voice work for Ghoul in the animated DCAU film Batman Beyond: Return of the Joker. Rosenbaum filmed the original SyFy comedy series Saved By Zeroes; yet was never picked up. He recurred in Fox's original sitcom Breaking In; the show was cancelled initially after the first season but got a second chance, and Rosenbaum was promoted to series regular. The series was cancelled again after a few episodes of the second season.
In 2014, Rosenbaum made his feature-film directorial and writing debut with the comedy Back in the Day, starring as an actor who returns to his hometown in Indiana for a class reunion. The film was filmed in Newburgh and Evansville, Indiana. Prior to the production of Back in the Day, Rosenbaum planned to direct another comedy film, titled Sorry is For Sissies. The film had a cast including Jon Heder, Colin Hanks and Jennifer Love Hewitt; however, at least half of the film's budget was lost, and the film was scrapped.
On June 17, 2014, Rosenbaum was cast as the lead in the TV Land original sitcom Impastor. The plot has been summarised as a "low-life who hides out in a small town by conning the residents into thinking he is their newly hired gay pastor".
In 2017, Rosenbaum served as narrator for the reality television show Hunted which pitted investigators against teams of ordinary citizens trying to evade capture as fugitives. Rosenbaum also starred in the Indie thriller The Neighbor opposite William Fichtner.
In 2018, Rosenbaum debuted his casual celebrity interview-based podcast called Inside of You. His first guest was his Smallville co-star Tom Welling. The two subsequently launched the podcast Talkville in July 2022, where they re-watch every episode of Smallville.
Rosenbaum reprised the role of Martinex in Guardians of the Galaxy Vol. 3, which premiered in May 2023.
In 2023, Rosenbaum's band Sun Spin released their second album, Never Is What It Is. That same year, Los Angeles Daily News reported that Rosenbaum and his longtime friend Jon Heder would star in the horror-themed reality television series Scared with Michael Rosenbaum and Jon Heder. Rosenbaum said of the project, "I wanted to do a reality show because we love horror movies. We'll go to the scariest places on Earth."
In 2024, Rosenbaum was the lead actor in the audio series TRUE NOIR: The Assassination of Anton Cermak. The series was penned by Road to Perdition's Max Allan Collins.
In 2025, Rosenbaum made a cameo in James Gunn's Superman as one of Lex Luthor's troopers, putting Eve Teschumer (Sara Sampaio) into a prison cell.
In 2026, Rosenbaum's band Sun Spin released their third album, Welcome to This life. That same year, Rosenbaum created and is executive producing an untitled project with Jeff Frost (Pluribus) and Joshua Michael Stern (Graves). Geena Davis is set to star.
