- O-Lan Jones (1 movie)
- O'Shea Jackson Jr. (2 movies)
- Oakes Fegley (1 movie)
- Ocean James (1 movie)
- Octavia Selena Alexandru (1 movie)
- Octavia Spencer (4 movies)
- Octavius J. Johnson (1 movie)
- Olek Krupa (1 movie)
- Olga Dihovichnaya (1 movie)
- Oliver Bigalke (1 movie)
- Oliver Chris (1 movie)
- Oliver Cooper (1 movie)
- Oliver Jackson-Cohen (1 movie)
- Oliver Platt (3 movies)
- Oliver Sindcup (1 movie)
- Oliver Stark (1 movie)
- Oliver Steer (1 movie)
- Olivia Bond (1 movie)
- Olivia Gillies (1 movie)
- Olivia Hamilton (1 movie)
- Olivia Kate Rice (1 movie)
- Olivia Munn (1 movie)
- Olivier Gourmet (1 movie)
- Olly Murs (1 movie)
- Omar Chaparro (2 movies)
- Omar Epps (1 movie)
- Omar Metwally (1 movie)
- Omar Sy (2 movies)
- Omari Bernard (1 movie)
- Onika Day (1 movie)
- Oona Laurence (3 movies)
- Ori Pfeffer (1 movie)
- Orlando Bloom (2 movies)
- Orlando Jones (1 movie)
- Orlando Schwerdt (1 movie)
- Oscar Flores (1 movie)
- Oscar Isaac (2 movies)
- Óscar Jaenada (2 movies)
- Oscar Nunez (1 movie)
- Ove Hoegh-Guldberg (1 movie)
- Owain Yeoman (1 movie)
- Owen Asztalos (2 movies)
- Owen Teague (1 movie)
- Owen Wilson (2 movies)