Early in his career, he gained recognition for his uncanny and hilarious impressions, particularly for that of stony Christopher Walken. He made his television debut as part of the Not Ready for Prime Time Players on NBC's Saturday Night Live. While on the show, Mohr received an Emmy nomination for his work.

After leaving SNL, Jay Mohr began guest starring on other shows and landed regular parts on The Jeff Foxworthy Show and Local Heroes. For hosting the MTV network's Lip Service, Mohr won an Espy Award. He made his feature film debut in 1995, with The Barefoot Executive, but gained real recognition playing Tom Cruise's rival sports agent, Bob Sugar, in Jerry Maguire (1995).

He hosted the talk-show Mohr Sports on ESPN, which began airing in 2002. Then, in 2003, he served as both host and executive producer on NBC's Last Comic Standing, a reality show that attempted to find the funniest undiscovered stand-up comedian in America.