Orson Welles adapted the novel as a one-hour radio play for the November 12, 1939, episode of the Campbell Playhouse. Welles himself played both Dr. Sheppard and Hercule Poirot.
- Adapter: Howard Koch and Wyllis Cooper
- Producer: John Houseman and Orson Welles
- Director: Orson Welles
Cast[]
- Orson Welles as Hercule Poirot and Dr. Sheppard
- Edna May Oliver as Caroline Sheppard
- Alan Napier as Roger Ackroyd
- Brenda Forbes as Mrs. Ackroyd
- Mary Taylor as Flora
- George Coulouris as Inspector Hamstead
- Ray Collins as Mr. Raymond
- Everett Sloane as Parker