Stephen Arlen (31 October 1913 – 19 January 1972) was an English theatre manager and operatic administrator. Originally an actor, he took up backstage work as a stage manager, and in the years after the Second World War was in charge of stage management at the Old Vic.
He was persuaded to join Sadler's Wells Opera as an administrator, and was the moving force behind the company's change of base from Sadler's Wells Theatre to the London Coliseum in 1968. He was seconded by Sadler's Wells to be adviser to the Théâtre Royal de la Monnaie in Brussels, and administrative director of the National Theatre in its early days.