O
- Katie O'Brien
- Nicholas A. O'Donoughue
- Claire E. O'Hanlon
- Kelsey O'Hollaren
- Angela O'Mahony
- Brenna O'Neill
- Allison J. Ober
- David A. Ochmanek
- Theodora Ogden
- Chad J. R. Ohlandt
- Edward N. Okeke
- Zhan Okuda-Lim
- Shona Olalere
- Stephen W. Oliver, Jr.
- Stuart S. Olmsted
- Fifi Olumogba
- V. Darleen Opfer
- Isaac M. Opper
- Scott Orr
- Bruce R. Orvis
- Jan Osburg