The Sign of Four
- Blwyddyn: 1983
- Gwlad: United Kingdom
- Genre: Adventure, Crime, Mystery, TV Movie
- Stiwdio: Granada Television, Mapleton Films
- Allweddair: treasure, river, doctor, pearl, sherlock holmes
- Cyfarwyddwr: Desmond Davis
- Cast: Ian Richardson, David Healy, Thorley Walters, Michael O'Hagan, Cherie Lunghi, Joe Melia