| Abbreviation | Definition |
|---|---|
| OTTC | Ontario and Trumansburg Telephone Company |
| OTTC | Our Time Theatre Company |
| OTTF | Old Town Tequila Factory |
| OTTP | Over The Top Performance |
| OTU | Official Traveller Universe |
| OTW | On The Waterfront |
| OTX | Ocwen Technology Xchange |
| OTY | O'Brien, Tanski & Young Attorneys |
| OU | Organizational Unit |
| OUBC | Ouachita Bank Corporation |
| OUG | Out U Go |
| OUH | Our Ultimate Home |
| OUI | Opportunities Unlimited Inc |
| OUM | Odenberg, Ullakko, Muranishi Co. LLP |
| OUM | Odenberg, Ullakko, Muranishi & Co. LLP |
| OUP-USA | Oxford University Press - United States of America |
| OUS | Oklahoma Upholstery Supply Company |
| OUS | Organizational Universe Systems |
| OUTB | Outback Oil & Mineral Exploration Corporation |
| OV | Oost Vlaanderen |