| Abbreviation | Definition |
|---|---|
| OHPL | Oak Harbor Public Library |
| OILLS | Online Inter-Library Loans System |
| OJD | Oxford Junior Dictionary |
| OKU | Olin Kroch Uris Libraries |
| OL | Olin Library |
| OL | On Loan (library) |
| OLA | Office for Library Advocacy |
| OLA | Oklahoma Library Association |
| OLBA | Ontario Library Boards Association |
| OLBA | Ontario Library Boards' Association |
| OLE | Open Library Environment |
| OLH | Open Library of Humanities |
| OLIG | Oxford Libraries Internet Gateway (UK) |
| OLIS | Oxford Libraries Information System |
| OLITA | Ontario Library and Information Technology Association |
| OLIVE | Online Library of Interactive Video and Engagement |
| OLL | Online Learning Library |
| OLL | Online Library of Liberty |
| OLL | Oracle Learning Library |
| OLLC | Ohio Law Library Consortium |