| Acronym | Definition |
|---|
| OAC | On Approved Credit |
| OAC | Ohio Athletic Conference |
| OAC | Ohio Administrative Code |
| OAC | Online Archive of California (California Digital Library) |
| OAC | Ohio Arts Council (Columbus, OH) |
| OAC | Ontario Arts Council (Canada) |
| OAC | Oklahoma Administrative Code |
| OAC | Ontario Agricultural College |
| OAC | Osservatorio Astronomico Di Capodimonte (Italian: Astronomical Observatory of Capodimonte; Naples, Italy) |
| OAC | Ontario Academic Credit |
| OAC | Open Air Campaigners (ministry) |
| OAC | Ontario Aerospace Council |
| OAC | Officer Advanced Course |
| OAC | Oklahoma Aeronautics Commission |
| OAC | Ontario Academic Credits |
| OAC | Office of Antiboycott Compliance |
| OAC | Ottawa Athletic Club (Canada) |
| OAC | Open Agility Certificate (Dog Agility Title) |
| OAC | Office of the Administrator for the Courts (Washington state agency) |
| OAC | On A Call |
| OAC | Objectivist Academic Center |
| OAC | Olympic Athletic Club (Seattle, Washington) |
| OAC | One Arm Chin-Up |
| OAC | Ohio Amish Country (Northeast Ohio) |
| OAC | Office of the Administrator of the Courts (Washington state) |
| OAC | Oceanic Area Control Center |
| OAC | Owner Architect Contractor |
| OAC | Operation Argument Complexity |
| OAC | Open Auto Classifieds (website) |
| OAC | Orthodox Anglican Church |
| OAC | Operand Address Calculation |
| OAC | Operating Agency Code |
| OAC | Ogihara America Corporation (metal stamping plant) |
| OAC | Oral Aspirin Challenge |
| OAC | Office Allegation Coordinator |
| OAC | Outdoor Advertising Council |
| OAC | Operator Assistance Centre (BT) |
| OAC | (Chiropractic) Oversight Advisory Committee (DoD) |
| OAC | Objective Assignment Chart (US Navy PPP based curriculum development) |
| OAC | Ohio Athletic Club (sweep rowing and sculling) |
| OAC | Original Airworthiness Certification |
| OAC | Office of Arms Control |
| OAC | Obstetric Assessment Clinic |
| OAC | Odd Autocorrelation |
| OAC | Orenda Aerospace Corporation (Canada) |
| OAC | Official Acceptance of Construction |
| OAC | Operations and Analysis Center |
| OAC | Organizational Activity Code |
| OAC | Oman Automobile Club (Muskat, Oman) |
| OAC | Optimum Approach Cruise |
| OAC | United States Army Ordnance Ammunition Command (Joliet, Illinois) |
| OAC | Operational Affairs Committee (Universal Postal Union) |
| OAC | Occupational Advisory Committee (various locations) |
| OAC | Oregon Arts Commission (est. 1967) |
| OAC | Open Access College (various locations) |