| Acronym | Definition |
|---|
| OPA➣Office of Public Affairs |
| OPA➣Ontario Power Authority (Ontario, Canada) |
| OPA➣Online Publishers Association |
| OPA➣Oil Pollution Act of 1990 |
| OPA➣Oil Painters of America |
| OPA➣Offre Publique d'Achat |
| OPA➣Oferta Pública de Adquisición (de Acciones) |
| OPA➣Oferta Publica de Adquisicion (Spanish) |
| OPA➣Online Payment Agreement (taxes) |
| OPA➣Otherwise Protected Area |
| OPA➣Opacity-Associated |
| OPA➣Office of the Provincial Agriculturist (Philippines) |
| OPA➣Online Pool Analyzer |
| OPA➣Optical Pre Amplifier |
| OPA➣Online Public Access |
| OPA➣Office of Price Administration |
| OPA➣Offerta Pubblica Di Acquisto (Italian) |
| OPA➣Office of Population Affairs |
| OPA➣Opsonophagocytic Assay (microbiology) |
| OPA➣Office of Protection and Advocacy (aka P&A; persons with disabilities; Connecticut) |
| OPA➣Office of the Patient Advocate |
| OPA➣Official Points of Acceptance (investing) |
| OPA➣Office of Public Advocacy (various locations) |
| OPA➣Office of Professional Accountability (Seattle Police Department) |
| OPA➣Oropharyngeal Airway |
| OPA➣Ontario Pharmacists' Association |
| OPA➣Office of Pharmacy Affairs (HHS) |
| OPA➣Optical Parametric Amplifier |
| OPA➣Online Privacy Alliance |
| OPA➣Open Patent Alliance |
| OPA➣Oklahoma Press Association |
| OPA➣Open Partial Agreement (EU) |
| OPA➣Outward Processing Arrangement (Hong Kong and China) |
| OPA➣Ohio Pharmacists Association |
| OPA➣Optic Atrophy |
| OPA➣Ontario Psychological Association |
| OPA➣Overseas Publishers Association |
| OPA➣Office of Payroll Administration |
| OPA➣Opera Primaziale Pisana (Italian social accountability policy) |
| OPA➣Ontario Parks Association (Canada) |
| OPA➣Office of Policy Analysis |
| OPA➣Other Procurement, Army |
| OPA➣Official Public Account (Australia) |
| OPA➣Office of Public Assistance |
| OPA➣Office of Planning and Analysis (various locations) |
| OPA➣Oregon Paralegal Association |
| OPA➣Ontario Prospectors Association |
| OPA➣Ontario Paramedic Association |
| OPA➣Office of Program Appraisal |
| OPA➣Offshore Petroleum Act 2006 (Australia) |
| OPA➣Oriented Polyamide |
| OPA➣Operations, Army |
| OPA➣Office of Premarket Approval |
| OPA➣Okinawa Prefectural Archives (est. 1995; Japan) |
| OPA➣Ortho-Phthaldialdehyde |
| OPA➣Optical Publishing Association |
| OPA➣Observations Programme Area (JCOMM) |
| OPA➣Other Principal Arterial (transportation) |
| OPA➣Outstanding Paper Award |
| OPA➣Offenporigen Asphaltdeckschicht (German: Porous Asphalt Surface Layer) |
| OPA➣Organization of Professional Aviculturists |
| OPA➣Offense Per Acre (gaming) |
| OPA➣Organization for Public Administration |
| OPA➣Orthopedic Professional Association (Gilford, New Hampshire) |
| OPA➣Ohio Poetry Association (Ohio) |
| OPA➣Officer Personnel Act |
| OPA➣Open Platform Architecture |
| OPA➣Organization of Professional Associations of Sri Lanka |
| OPA➣Office of Professional Attachment |
| OPA➣Out of Place Artifact |
| OPA➣Orthopaedic Practice Assembly (Medical Group Management Association) |
| OPA➣Overarching Partnering Agreement |
| OPA➣Ontario Physiotherapists Association |
| OPA➣Ouptut and Performance Analysis |
| OPA➣OSI Presentation Address |
| OPA➣Operations Procurement Authority |
| OPA➣Other Procurement Authority |
| OPA➣Open Planar Array |
| OPA➣Overhead Precautionary Approach |
| OPA➣Organizational Performance Architecture |
| OPA➣Operator Panel Assembly |
| OPA➣Outage Probability Analysis |