| Abbreviation | Definition |
|---|---|
| OCSI | One Call Systems International |
| OCSI | Oxford Consultants for Social Inclusion |
| OCT | On Company Time |
| OCT | Ouellet Carter And Tumaroff |
| OCTC | Ocean City Theatre Company |
| OCZ | Overclockerz Store |
| OD | Office Depot |
| OD | Oregon Diner |
| ODBE | Open Designers and Buyers Event |
| ODBEC | Open Designers and Buyers Events Club |
| ODBS | Online DataBase Solutions |
| ODC | Oak Design Corporation |
| ODC | Oberbroeckling Development Company |
| ODC | ODCDance Company |
| ODC | Odessa Development Corporation |
| ODC | Offshore Development Center |
| ODC | Oil Development Company |
| ODC | Oil Dri Corp |
| ODC | Oil Dri Corporation |
| ODC | Oneonta Dairy Company |