| Label | Country | Founded | Label type |
|---|---|---|---|
| Offshore Music Limited | — | 2010 | Publisher |
| Ohr | — | — | — |
| Om Records | — | 1995 | Original Production |
| Omnicore Records | Germany | 2021 | — |
| On Board Music | — | — | Original Production |
| Ordinamento Selettivo | Italy | December 26, 2016 | Imprint |
| Original Dub Gathering | France | 2005 | — |
| Oscillation Records | — | — | — |
| Osisa records | Ireland | June 17, 2023 | Original Production |
| Oslated | — | 2016 | Imprint |
| Oslo Records | — | — | — |
| Ostgut Ton | Germany | 2005 | Original Production |
| Ostgut Ton | — | — | — |