| Abbreviation | Definition |
|---|---|
| OOTE | Order Of The Elephants |
| OOTH | Orchestra on the Hill |
| OOTS | Orchestra of the Swan |
| OP | On point |
| OP | Organic Percussion |
| Op. | Opus number |
| OPB | Oasis Praise Band |
| OPCM | Oakland Public Conservatory of Music |
| OPF | Orchestra Parents And Friends |
| OPM | Original Pilipino Music |
| OPM | Original Pinoy Music |
| OPM | Other People's Music |
| OPM | Overflow of Praise Music |
| OPMI | Orlando Premier Music Instruction |
| OPP | Other People's Property |
| OPPB | Orchestre de Pau - Pays de Béarn |
| OS | Organ Series |
| OSCA | Oklahoma Songwriter`s and Composer`s Association |
| OSCAR | Online Song Contest Accumulated Ranking |
| OSG | On Sight Gang |