- O'Connor, Michael1
- O'Neil, Griffin1
- O'Neil, Kara1
- O'sullivan, Finbarr1
- Olson, Adam1
- Onffroy, Maxwell2
- Onyenokwe, Chioma M.1
- Ortega-Shue, Sage1
- Osei, Michael1
- Oshiro-Leavitt, Clay N.1
- Osterloh, Emily A.1
- Ostrum, Taylor1
- Ou, Baian1
- Ouellette, Cole1
- Ouellette, Daniel1
- Ourdyl, Tarik1
- Owuor, Hezi1
- Owusu, Evans1