Michael was born in Watford, Hertfordshire to an English mother and Peruvian father. He was well educated at a Folkestone private school and Eton College, then served as an intelligence officer in the RAF during World War Two.

On leaving the service he became a comedian and script-writer and was the first of the Goons to make it into London's West End.

Michael was a founder member of the Goon Show, but left after the second series before the show reached the peak of success. Creative friction between him and Milligan, plus his own ambitions are given as reasons for his departure.

He went on to perform and write many TV/radio shows, books and much more. Despite this he is still remembered by many as the "other" Goon. Very few of the early episodes that Bentine appeared in have survived, so his contribution to the show is frequently overlooked.

In 1995 Bentine received a CBE for Services to Entertainment. He was married once and had two children (Richard and Serena) with his wife Clementina.