Oers
- Paul
- Oersted
- Oersted , Hans Christian
- Ohm , Georg Simon
- Olah , George Andrew
- Olbers , Heinrich
- Oldham , Richard Dixon
- Oliphant , Marcus Laurence Elwin
- Omar Khayyam
- Onsager
- Onsager , Lars
- Oort , Jan Hendrik
- Oppenheimer , Julius Robert
- Osheroff
- Osheroff , Douglas