Catherine Mary Stewart's career has spanned more than 30 years and over 50 different productions, from film to television to theater, in England, Canada and the United States. She was living in London studying dance, acting and singing when she was cast in her first professional acting role as the lead in the rock musical The Apple (1980), which was chosen to open the Montreal World Film Festival in 1980 and has since developed a cult following, being screened - twice, due to popular demand - at Lincoln Center in New York City.

Catherine moved to Los Angeles in 1981 and soon landed a contract with Days of Our Lives (1965), originating the role of Kayla Brady. During Catherine's tenure with the soap opera, she was cast in the lead role of Maggie Gordon in The Last Starfighter (1984). She found steady employment in films, appearing in a variety of films including the cult classic Night of the Comet (1984), the teen comedy Mischief (1985) and the female lead in the comedy film Weekend at Bernie's (1989).