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- Oliver! (1968) - Jack Wild
- On the Waterfront (1954) - Lee J. Cobb
- On the Waterfront (1954) - Karl Malden
- On the Waterfront (1954) - Rod Steiger
- One Flew Over the Cuckoo's Nest (1975) - Brad Dourif
- Only When I Laugh (1981) - James Coco
- Ordinary People (1980) - Judd Hirsch
- Ordinary People (1980) - Timothy Hutton
- Othello (1965) - Frank Finlay
- Out of Africa (1985) - Klaus Brandauer
Read more about this topic: List Of Nominees For The Academy Award For Best Supporting Actor (by Film Title)