Before his time in Hollywood, Robert Hays lived in San Diego, CA (Pacific Beach) and picked up little acting gigs in San Diego's local theater scene. He had several roles at the world famous Old Globe Theatre, including the leading role as PetrucciO' in a touring production of William Shakespeare's The Taming of the Shrew. Shortly after the Shrew gig, Hayes moved to Hollywood where he found quick success.
Hays has starred in several short-lived television series, including the 1978 production The Young Pioneers on ABC, the 1979 series Angie, and Starman, on which he played the title character and FM. He played the role of Bud, the man thought to be Hyde's dad, in several episodes of That 70s Show. Hays has also directed and produced for films and television.
He has also performed in many television movies and has done voice work such as the title character on the Marvel Comic adaptation of Iron Man. In 2013, Hays appeared in a slapstick-laden TV spot promoting tourism in Wisconsin, which also reunited him with Airplane! co-director David Zucker.