- Oklahoma Panhandle State University
- Oklahomas
- Oklahoma State University
- Oklahoma State Univ Tech Branch-Oklahoma City
- Oklahoma State Univ Technical Branch-Okmulgee
- Okmulgee
- Okolona
- okra
- okras
- okro
- OKs
- OK's
- Oktoberfest
- Oktoberfests
- oktō(u)
- -ol
- -ol
- Olaf II
- Olathe
- Olav II
- old
- old
- old boy
- old-boy network
- Old Bulgarian