During the 1930s he performed regularly in the so-called "quota quickies". One of his earliest roles was as the heroic lead in the 1937 film The Last Adventurers. He appeared in the film In Which We Serve (1942) and also in the Hitchcock film Stage Fright (1950). He featured as Detective Inspector Berkeley in one episode of Edgar Lustgarten's drama series, Scotland Yard ("Person Unknown", 1956). He made a brief appearance in the American film National Lampoon's European Vacation which starred Chevy Chase. In this film, Berkeley played a British man who is involved in a minor road accident with the Griswalds.

Berkeley played the role of the bumbling Major Gowen in the BBC TV comedy Fawlty Towers. He had played a similar role in 1969 in the legal drama The Main Chance. He portrayed another retired military man (Colonel Freddie Danby) in BBC Radio 4's The Archers, taking over the role from Norman Shelley.

He played a starring role in Fresh Fields as main character Hester's father Guy, was Uncle Greville in To the Manor Born, and played Colonel Culpepper in Terry and June. He had small roles in an episode of Citizen Smith (1977) and an adaptation of Little Lord Fauntleroy (1980), and appeared once in The New Avengers as Colonel Foster in the episode "Dirtier by the Dozen". He had a small role in an episode of the BBC sitcom Hi-de-Hi! ("Empty Saddles", 1983).

Berkeley later performed the role of Winston – a similar character to "The Major" – in the radio comedy Wrinkles by Doug Naylor and Rob Grant. He played Badedas the Blue, a wizard in the radio comedy series Hordes of the Things. His last role was as the Head of the Army in the animated film version of Roald Dahl's The BFG. He died in 1988, and the film was released the following year.