Cyd Hayman's initial aspiration was to pursue a career in journalism, but she eventually shifted her focus to acting after attending the London Academy of Music and Dramatic Art (LAMDA). To fund her tuition fees, she took on various jobs, which ultimately led her to work in repertory theatre in Liverpool, Ipswich, Folkestone, and the Mermaid in London.
Before landing her breakout role on television, Hayman had already made appearances in several notable productions. In 1956, she appeared in Armchair Theatre, and in 1963, she starred in Love Story. Her early work with the BBC included roles in The Wednesday Play (1964) and other notable performances in Manhunt (1970),in which she played the leading role of Nina.
Hayman's impressive television career continued with roles in Clochemerle (1972),The Lotus Eaters (1972),The Persuaders! (1971),Crime of Passion (1970),The Rivals of Sherlock Holmes (1971),and The Two Ronnies (1971). Her film credits include Percy (1971) and Guns Before Butter (1994).