O
- Katie O'Brien
- Nicholas A. O'Donoughue
- Claire E. O'Hanlon
- Angela O'Mahony
- Brenna O'Neill
- Fin Oades
- Allison J. Ober
- David A. Ochmanek
- Daniel Oesterle
- Theodora Ogden
- Chad J. R. Ohlandt
- Jacob Ohrvik-Stott
- Edward N. Okeke
- Zhan Okuda-Lim
- Adeyemi Okunogbe
- Stephen W. Oliver, Jr.
- Stuart S. Olmsted
- V. Darleen Opfer
- Isaac M. Opper
- Scott Orr
- Bruce R. Orvis
- Jan Osburg
- Osonde A. Osoba
- Umut Ozek