Sullivan is a San Francisco native who began his career as a child actor. The youngest of three children, he grew up in St. Francis Square in the Fillmore district. His father was a bus driver, and his mother was a receptionist for St. Mary's Hospital. According to Sullivan, he was "one step up from a housing project". During sixth grade while performing in ''
A Midsummer Night's Dream'', Sullivan's talents were noted by Ann Brebner, who hired him and his entire class as extras in a 1970 Sidney Poitier film,
They Call Me Mr. Tibbs!. This was his first experience with cinema. Brebner would continue to give Sullivan various auditions. In 1970, he was cast in an
Alpha-Bits Cereal commercial, earning over $7,000. He continued to obtain small roles in theater productions and doing commercials. Most notably, he got a role as the Master of Ceremonies during an episode of
Sesame Street being filmed live at
Golden Gate Park. He had to "sit on this big garbage can with a microphone and introduce the various skits," with
Jim Henson controlling the puppets. "The school had 1,200 boys; only 40 were black," according to Sullivan. Sullivan was challenged in his classwork for the first time; he was also barred from the theater program because of his race. "I felt out of place and no one tried to make me feel otherwise," said Sullivan. At one point, he joined the
Young Conservatory of the American Theater in downtown San Francisco. During his senior year, he convinced the theater department to allow him to direct
Ceremonies in Dark Old Men, by
Lonne Elder; following this, the school asked him to be the lead in a production of
The Teahouse of the August Moon. Due to his acting successes, Sullivan applied to the
Juilliard School in New York.
John Houseman, who had recently received an Oscar for his role in
The Paper Chase, was his interviewer. Houseman's comments on Sullivan's abilities at the time: "You have talent, but you're only 17 years old. Most of our students come here after four years of college. I don't think you're ready for New York City just yet." Sullivan ended up at
Willamette University in
Salem, Oregon, where he was offered a theater scholarship. He applied to be an
English major, as hewas growing increasingly interested in writing. "I was a whale in a fishbowl," said Sullivan, who was overqualified for the college's theater program.He played the lead, Proteus, in
Two Gentlemen of Verona, rather than the supporting role for which he had auditioned. Subsequently, Sullivan was in numerous plays and was chosen to direct a production of
Slow Dance on the Killing Ground, a play by
William Hanley. He decided to produce his own play as an independent study, left Willamette and never went back. In the summer of 1987, Sullivan headed to
Los Angeles. He began by working with a friend and fellow actor in
Hollywood and began to write scripts. On one four-day trip to
DC, he picked up inspiration for characters from fellow passengers. While his scripts went largely unnoticed, the trip would inspire later works. In the meantime, his acting was noticed after he auditioned for a few movie roles, including Lieutenant in
More American Graffiti (1979), Tyrone in
Night Shift (1982), March in
Star Trek II: The Wrath of Khan (1982), and John Grant in
The Adventures of Buckaroo Banzai Across the 8th Dimension (1984). ==Early screenwriting==