| OPEC | Obese Penguins Eating Cars 
| Others |
| OPEC | Office Of Petrol And Electricity Consumption
| Others |
| OPEC | Office of Prevention Education and Control
| Others |
| OPEC | Office of Prevention, Education, and Control
| Others |
| OPEC | Office of Programs for Exceptional Children
| Others |
| OPEC | Office of Public and Employee Communications
| Others |
| OPEC | OFI Private Equity Capital
| Others |
| OPEC | Ohio Prevention and Education Conference
| Others |
| OPEC | Oil and Petroleum Exporting Countries
| Others |
| OPEC | Oil Producing and Exporting Countries
| Others |
| OPEC | Oil Producing Exporting Countries
| Others |
| OPEC | Oil Profits Eat Consumers
| Others |
| OPEC | Old People Eat Cake
| Others |
| OPEC | Old People Eating Chicken
| Others |
| OPEC | Ongoing Petrol Energy Crisis
| Others |
| OPEC | Only People Eat Cows
| Others |
| OPEC | Open Patios Expect Chairs
| Others |
| OPEC | Orange Pineapples Enter Contests
| Others |
| OPEC | Ordinary People Expecting Change
| Others |
| OPEC | Oregon Parenting Education Collaborative
| Others |
| OPEC | Organisation of Petroleum Exporting Countries
| Others |
| OPEC | Organization for Petroleum Exporting Countries
| Others |
| OPEC | Organization of People for Energy Conservation
| Others |
| OPEC | Organization of Petroleum Exporting Countries
| Others |
| OPEC | Organization of Preppies that Eat Cheese
| Others |
| OPEC | Organization of the Petroleum Exporting Countries
| Others |
| OPEC | Overflowing Porta-potties Excrete in China
| Others |
| OPEC | Overly Protective Egyptian Caskets
| Others |