He began his stage experience at the theatre club next to the Palace Court Hotel in Bournemouth, where he was a last-minute cast replacement in The Beaux' Stratagem.

He later made his first professional stage appearance under his given name, Donald Gray, as Charles the Wrestler in Roger Atkins' production of As You Like It.

Charles Gray distinguished himself in theatrical roles, in the Regent's Park Open Air Theatre, London, at the Royal Shakespeare Company, Stratford-Upon-Avon and at the Old Vic.

His breakthrough year was 1967, when he starred with Peter O'Toole and Omar Sharif in the Second World War murder-mystery film The Night of the Generals.

[1] The same year, he played Dikko Henderson, a British intelligence officer assigned to their Embassy in Tokyo, in the Bond film You Only Live Twice (1967).

From this period, he is perhaps best known for portraying the Criminologist (the narrator) in The Rocky Horror Picture Show and a similar character, Judge Oliver Wright, in its sequel Shock Treatment (1981).

In 1973, he played Lord Seacroft in the television series The Upper Crusts opposite Margaret Leighton, and in 1983, he starred alongside Coral Browne and Alan Bates in the award-winning made-for-TV film An Englishman Abroad.