Harris was born in Limerick, Irish Free State on 1 October 1930 to an Irish Catholic family. Harris studied to become an actor at the Crescent College and at The Royal Academy of Music and Dramatic Art. Harris was married to Elizabeth Rees-Williams from 1957 until they divorced in 1969. Harris remarried in 1974 to Ann Turkel until they divorced in 1982. Harris has three sons: Jamie Harris, Jared Harris, and Damian Harris. 