Holliday's longest-running role on Broadway was that of Richard Kiley's alternate as Don Quixote in "Man of La Mancha", playing Don Quixote in matinees and Dr Carrasco in the evening performances, from 1965 to 1971 (and later took on the role of the innkeeper in the 1992 revival). His next performance, as Georges in "Coco", (1969 – 1970) earned him a Theatre World Award. He also appeared in the musicals "Nevertheless They Laugh" (Off Broadway 1971), "Music Is" (1976) and "Perfectly Frank" (1980).