On stage, after a wealth of London fringe theatre experience, Bentinck starred as the Pirate King in The Pirates of Penzance at the Theatre Royal, Drury Lane in 1982, as Captain Brice in Arcadia at the Theatre Royal, Haymarket, and as Hubert Laurie in Night Must Fall, also at the Haymarket. Bentinck tours a one-man show, Love Your Chocolates, - a mixture of stories, comedy songs and multi-media, and played Frank in Educating Rita at the Watermill Theatre, Newbury, Berkshire, in 2009.