| Abbreviation | Definition |
|---|---|
| OLLC | On Line Library Center |
| OLLC | Online Library Learning Center |
| OLS | Office of Library |
| OLS | Office of Library Services |
| OLS | Online Library System |
| OMED | Oxford Modern English Dictionary |
| OML | OCaml Math Library |
| OML | OMF Measurement Library |
| OOL | Open Optimization Library |
| OOML | Object Oriented Mechanical Library |
| OOML | Object Oriented Mechanics Library |
| OOPL | Olusegun Obasanjo Presidential Library |
| OPAC | Online Public Access Computer |
| OPAC | Open Public Access Catalog |
| OPAL | Ohio Private Academic Libraries |
| OPAL | Open Phone Abstraction Library |
| OPC | Online Public Catalog |
| OPL | Oakland Public Library |
| OPL | Omaha Public Library |
| OPL | Online Proceedings Library |