Born October 16, 1958 in West Covina, California. He was the fourth and final child of devout Roman Catholic parents. His father, Gil Robbins, was the director of the congregational choir. Gil was also a successful folk-singer, and not too many years after the birth of his youngest son, he moved the family to Greenwich Village in New York City, where he won ephemeral fame as a member of the Highwaymen. Robbins's mother, Mary, broke into the magazine industry as a publishing executive.

He made his performing debut alongside his father on a duet of the protest song Ink Is Black But the Page Is White. At the age of 12 Robbins joined the Theatre for the New City, remaining a member for the next seven years; he also joined his high-school drama club at Stuyvesant High School, an experience which afforded him his first opportunities to direct for the stage.

After briefly attending the State University of New York at Plattsburgh, he relocated to Los Angeles and worked for a year to establish California residency before enrolling at U.C.L.A., where he paid his way by delivering pizzas and by busing tables at the Hillcrest Country Club.

At U.C.L.A. he also joined the Male Death Cult, an intramural softball team comprised of his fellow drama students. In the year following his graduation(1981), the members of Male Death Cult reunited to establish the Actor's Gang, an avant-garde theater troupe whose efforts were focused on the works of such notables as Bertolt Brecht and Alfred Jarry. About this time, Robbins began appearing in movies (a small role in 1983's Toy Soldiers marked his big-screen debut), originally with the goal in mind of raising funds for the Actor's Gang.

Movies became more of a serious artistic ambition for Robbins after he won the central role of pitching phenom "Nuke" LaLoosh in Bull Durham in 1988. An onscreen romance with co-star Susan Sarandon in Bull Durham soon expanded into their offscreen lives as well. It eventually became a common-law marriage.

After Bull Durham came out and was successful, he was able to not have to be in LA to audition. Scripts are coming to him, so he moved back home to New York.

The Actors Gang has received numerous Drama-Logue, LA Weekly, and Ovation Awards, and in 1988 received the prestigious Margaret Hartford Award for "continued excellence." Robbins himself was honored with the LA Weekly Award for his direction of the Gang's debut production, a midnight performance of Ubu Roi, and earned a nomination for Best Director from the Los Angeles Drama Critics Circle for the group's production of Brecht's The Good Woman of Setzuan. Robbins is responsible for production with the Actors Gang and still serves as Founding Artistic Director with the group to this day.

In 1992, As an actor, Robbins received critical acclaim for his portrayal of the amoral studio chief in Robert Altman's The Player, a performance that earned him the Best Actor Award at the Cannes Film Festival and the Golden Globe Award for Best Actor in a Musical or Comedy.

That same year, he wrote, directed, starred and performed the music in Bob Roberts, a mock-documentary brutally parodying right-wing politics. Bob Roberts was nominated for a Golden Globe Award(best actor) and won three awards, including Best Film, at the Boston Film Festival. Robbins also executive-produced The Typewriter, the Rifle and the Movie Camera, a documentary about filmmaker Sam Fuller, which won the 1996 CableACE Award for Best Documentary.