Stephen Glenn Martin is an American comedian, writer, producer, actor, musician and composer born in Waco, Texas and raised in Orange County, California.

Martin worked at the Bird Cage Theatre in Knott's Berry Farm and at the Magic Shop at Disneyland as a teenager, where he developed his talents for magic, juggling, playing the banjo and creating balloon animals.

Martin majored in philosophy at California State University, Long Beach, but dropped out. Nevertheless, his time there changed his life: "It changed what I believe and what I think about everything. I majored in philosophy. Something about non sequiturs appealed to me. In philosophy, I started studying logic, and they were talking about cause and effect, and you start to realize, "Hey, there is no cause and effect! There is no logic! There is no anything!" Then it gets real easy to write this stuff, because all you have to do is twist everything hard — you twist the punch line, you twist the non sequitur so hard away from the things that set I up, that it's easy... and it's thrilling."

Martin's girlfriend in 1967 was a dancer on The Smothers Brothers Comedy Hour and helped Martin land a job as a writer for the program. Along with the other writers for that show, Martin won an Emmy Award in 1969. Martin also wrote for John Denver (a neighbour of his in Aspen, Colorado at one point) and The Glen Campbell Goodtime Hour.

He then started performing his own material, sometimes as an opening act for groups such as The Nitty Gritty Dirt Band and The Carpenters, after which began writing for such variety shows as The Smothers Brothers Comedy Hour, The Glen Campbell Goodtime Hour, and The Sonny and Cher Comedy Hour. He also appeared on these shows, and numerous others, in numerous comedy skits.

He appeared at San Francisco's The Boarding House among other locations. He continued to write, earning an Emmy nomination for his work on Van Dyke and Company in 1975.

In the mid-1970s he made frequent appearances as a stand-up comedian on The Tonight Show with Johnny Carson. That exposure, together with appearances on NBC's Saturday Night Live (SNL), led to his first of four comedy albums, Let's Get Small. The album was a huge success; one of its tracks, Excuse Me, helped establish a national catch phrase.

His next album, A Wild and Crazy Guy, was an even bigger success reaching the number two spot on the chart, and spawning another catch phrase, this time based on an SNL skit where Martin and Dan Aykroyd played a couple of bumbling Czechoslovakian playboys. A top 40 hit King Tut, from the album, released in 1978, was backed by the Toot Uncommons (better known as the Nitty Gritty Dirt Band). Both were million sellers. Both albums won Grammys for Best Comedy Recording in 1977 and 1978.

In these and his two other albums, Martin's stand-up comedy was self-referential, sometimes self-mocking. It mixes philosophical riffs with sudden spurts of "happy feet", deft banjo playing with balloon depictions of concepts like venereal disease. His style is off kilter and ironic, and sometimes makes fun of stand-up comedy traditions. A typical gag might be interrupted for a sip from a glass of water, and just as he was about to speak again, he forcefully spits the water onto the floor.

By the end of the 1970s, he had acquired the kind of following normally reserved for rock stars, with his tour appearances typically occurring at sold-out arenas filled with tens of thousands of screaming fans. But unknown to his audience, stand-up comedy was "just an accident" for him. His real goal was to get into film.

Martin's first film was a short, The Absent-Minded Waiter (1977). The seven-minute long film, also featuring Buck Henry and Teri Garr, was written by and starred Martin. The film was nominated for an Academy Award as Best Short Film, Live Action.

In 1979, Martin wrote and starred in his first full-length movie, The Jerk, directed by Carl Reiner. The movie was a huge success, grossing $100 million on a budget less than a twentieth of that amount.

The success of The Jerk opened more doors for him. Stanley Kubrick met with him to discuss him starring in an early, screwball comedy version of Traumnovelle (Kubrick later changed his approach to the material). He was executive producer for a prime-time TV series starring Martin Mull and a late-night series called Twilight Theater. It emboldened him to try his hand at his first serious film, Pennies From Heaven, a movie he was anxious to do because of the desire to avoid being typecast. To prepare for that film, he took acting lessons from the director, Herbert Ross, and spent months learning how to tap dance. The film was a financial failure; Martin's comment at the time was "I don't know what to blame, other than it's me and not a comedy."

Martin was in two more Reiner-directed comedies after The Jerk: Dead Men Don't Wear Plaid in 1982, and The Man with Two Brains in 1983.

In 1986, Martin joined fellow Saturday Night Live veterans Martin Short and Chevy Chase in ¡Three Amigos!, which was directed by John Landis, and written by Martin, Lorne Michaels and Randy Newman. It was originally entitled The Three Caballeros and Martin was to be teamed with Dan Aykroyd and John Belushi.

In 1987, Martin joined comedian John Candy in the John Hughes film, Planes, Trains & Automobiles. That same year, Roxanne, a film he cowrote, won him a Writers Guild of America award and more importantly, the recognition from Hollywood and the public that he was more than a comedian.

Martin starred in the Ron Howard film, Parenthood in 1989. In the same year, 1991, Martin starred in a lighthearted comedy (L.A. Story) and an existentialist tragedy (Grand Canyon) that were both about the city of Los Angeles. In 1999, Martin and Goldie Hawn starred in a remake of the 1970 Neil Simon comedy, The Out-of-Towners.