Following his mother's successful career as a divorce lawyer, in which she represented actresses Elizabeth Taylor and Roseanne Barr in their divorce settlements, the family moved to Beverly Hills, where Schwimmer attended Beverly Hills High School. Schwimmer admitted to being an outsider during his time at the school. Also a troublemaker and a bully, he did not fit in with the other kids. "When I was there I always felt: 'this is not me, I'm surrounded by people with a different value system. And I just wanted to get out of California.'" He was best at the subjects of science and math and thought he would become a doctor. Schwimmer enrolled in a drama class, where he appeared in stage productions. Encouraged by his school drama teacher to further his acting, he flew off to Chicago for an acting workshop. He noted that the experience was both "enlightening and exhilarating."
In 1984, Schwimmer graduated from Beverly Hills High, and wanted to go straight into acting, but his parents insisted he go to college first so he would have something to fall back on, in case his acting career did not work out. Schwimmer moved to Chicago to attend Northwestern University, where he had attended a summer drama course when he was 16 years old. At the university, he enrolled as a theater major, joining Delta Tau Delta Fraternity and Arts Alliance. After graduating in 1988, with a Bachelor of Arts degree in theater and speech, Schwimmer co-founded the Lookingglass Theatre Company. Subsequently, he returned to Los Angeles to pursue an acting career.
His family subsequently moved to Los Angeles, where Schwimmer had his first experiences of acting at the age of 10 when he was cast as the fairy godmother in a Jewish version of Cinderella. In 1979, Schwimmer went to a Shakespeare workshop given by English actor Ian McKellen in Los Angeles. He recalls that he was riveted by the experience. Schwimmer then entered a contest in the Southern California Shakespeare Festival three years in a row, winning two first prizes.
In 1989, Schwimmer made his television debut in the ABC movie A Deadly Silence, where he was cast in a supporting role. He followed this with roles on the legal drama L.A. Law in 1992, and the comedy-drama series The Wonder Years. He made his feature film debut in Crossing the Bridge (1992).Schwimmer had a recurring role as a lawyer-turned-vigilante in NYPD Blue and appeared briefly in ER in 1993, before auditioning, unsuccessfully, for a series pilot called Couples. He landed his first regular series role as the liberal son of a conservative talk show host (Henry Winkler) in the sitcom Monty.