| Abbreviation | Definition |
|---|---|
| OISPA | Occupational Injury Surveillance of Production Agriculture |
| OLRT | Organic Late-harvest Regional Trial |
| OMAFRA | Ontario Ministry Of Agriculture Food And Rural Affairs |
| OMAFRA | Ontario Ministry of Agriculture, Food and Rural Affairs |
| OMSB | Oldman Saltbush |
| OOTF | Out of the Farm |
| OPB | Ontario Potato Board |
| OPDP | Oil Palm Development Programme |
| OPGMB | Ontario Potato Growers' Marketing Board (19761999) (see OPB) |
| OPGMB | Ontario Potato Growers' Marketing Board (1976–1999) (see OPB) |
| OQRF | Old Quail Run Farm |
| OQW | Operation Quality Wheat |
| OSAP | Oberlin Sustainable Agriculture Project |
| OSCIA | Ontario Soil and Crop Improvement Association |
| OTFI | Old Town Farm Inn |
| OTTO | Off Track Throughobred |
| OUALA | Ownership and Use of Agricultural Land Act |
| OUAT | Orissa University of Agriculture and Technology |
| OVP | Organic Vegetable Production |
| OWBM | Orange Wheat Blossom Midge |