Clive was also known as an actor, who started his career at the age of fifteen. Later he appeared on the West End stage, in plays such as Absurd Person Singular, The Wizard of Oz, Under Milk Wood, The Bandwagon at the Mermaid Theatre, The Winslow Boy, Young Woodley and Life With Father. Clive's character acting has led him to appear in comic and serious roles in films, such as The Italian Job, Yellow Submarine, The Pink Panther Strikes Again, A Clockwork Orange and The Young Indiana Jones Chronicles. He also appeared in two of the Carry on series of comedy films; Carry On Abroad, and Carry On Dick.
Other notable film appearances include the Ealing Studios comedy The Magnet, credited as Clive Kendall. In the Beatles' animated film Yellow Submarine, he featured as the voice of John Lennon. His television appearances also included Robert's Robots, Rising Damp, The Dick Emery Show, The Perils of Pendragon, The Sweeney, Great Expectations and The History of Mr Polly. He appeared in the first Wednesday Play, Wear a Very Big Hat, broadcast by BBC 1 in 1964. Clive also featured in, Lady Windermere's Fan, One Way Out and The Ten Percenters.
In 1977, he co-wrote, with J.D. Gilman, the historical novel KG 200, a story about a secret Luftwaffe unit during the Second World War. “KG 200” was an international best-seller. The Last Liberator, his next book followed in 1980, and was well received by literary critics. Barossa (1981) also achieved critical acclaim. Broken Wings was published in 1983 and matched the international success of KG 200. Other fictional titles written by Clive include, Ark (1986) another book well received by critics and co-written with Nicholas Head. The Lions Cage was published in 1988.
John Clive died after a short illness on 14 October 2012 in England.