| Abbreviation | Definition |
|---|---|
| OHSHC | Ouran High School Host Club |
| OINP | Over Issue News Paper |
| OIQ | Olympia Institute Quarterly |
| OIRT | Organisation International de Radio et Télévision |
| OIW | Our Indian Wards (by George W. Manypenny, published in 1880) |
| OJ | Oh Joy |
| OK | All Correct |
| OKG | Oklahoma Gardening |
| OKV | Original Karaoke Version |
| OLD | Orchid List Digest |
| OLIVER | On Line Interpretive Video Editing Resource |
| OLL | Ohio Legislature...Live! |
| OLM | On Line Media |
| OLT | On- Line Tonight |
| OLW | One Last Word |
| OMA | Oregon Mediation Association |
| OMAI | Office of Media and Arts International |
| OMAP | Open Media Applications Platform |
| OMB | Opening Music Billboard |
| OMBC | Online Media Briefing Center |