Best known as Ted Striker from Airplane! Hays was born in Bethesda, Maryland. Before relocating to Hollywood, where he found quick success, Hays lived in the Pacific Beach area of San Diego, and picked up acting roles in San Diego's local theater scene. He worked in several productions at the famous Old Globe Theatre, including the role of Petruchio in a touring production of William Shakespeare's The Taming of the Shrew.
In 1977, Hays played a role in the television series Wonder Woman, playing a military corporal, Hays has starred in several short-lived television series, including the 1978 production The Young Pioneers on ABC; the 1979 series Angie; the science fiction series Starman, in 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 performed in many television movies and has done voice work such as the title character on the Marvel Comics 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. Other credits include Homeward Bound: The Incredible Journey (1993), and Stephen King's Cat's Eye (1985).