| Abbreviation | Definition |
|---|---|
| OASLMS | Oklahoma Association of School Library Media Specialists |
| OBA | Openbare Bibliotheek Amsterdam |
| OBS | OBSolete |
| OCD | Oxford Classical Dictionary |
| OCL | Ocean County Library |
| OCL | Ocean County Library's |
| OCL | Online Clinical Library |
| OCL | Ontario Community Literacy |
| OCL | Open Cezeri Library |
| OCL | Open Course Library |
| OCL | Oracle Class Library |
| OCL | Orangeburg County Library |
| OCL | Oxford County Library |
| OCLA | Orange County Library Association |
| OCLC | Ohio College Library Catalog |
| OCLC | Ohio College Library Center |
| OCLC | Online Computer Library Catalog |
| OCLC | Ortigas Center Library Consortium |
| OCLS | Off Campus Library Services |
| OCLS | Online Curriculum Library Services |