| Acronym | Definition |
|---|
| ORCA | Online Representations and Certifications Application |
| ORCA | Office of Rural Community Affairs |
| ORCA | Oregon Caves National Monument (US National Park Service) |
| ORCA | One Regional Card for All (public transit, Puget Sound, Washington) |
| ORCA | Ontario Residential Care Association |
| ORCA | Ocean Resources Conservation and Assessment |
| ORCA | Orca Relief Citizens' Alliance |
| ORCA | Outdoor Recreation Coalition of America (trade association for outdoor recreation businesses and organizations) |
| ORCA | Ontario Recreational Canoeing Association (now Ontario Recreational Canoeing and Kayaking Association; Canada) |
| ORCA | Open, Reliable Communications Architecture |
| ORCA | Online Research Collections Australia |
| ORCA | Old Reel Collectors Association (fishing reel collectors) |
| ORCA | Organized Readers of Comics Associated |
| ORCA | Optimized Robot for Chemical Analysis |
| ORCA | Ocean Racing Catamaran Association |
| ORCA | Object-oriented Requirements Capture and Analysis |
| ORCA | Optical Relay Communications Architecture (US National Reconnaissance Office; now defunct) |
| ORCA | Operational Requirement-Based Casualty Assessment |
| ORCA | Overboard Recovery Communications Apparatus (BriarTek Inc.) |
| ORCA | Options ROM for Configuring Arrays (HP servers) |
| ORCA | Operations Research & Computational Analysis (Sandia National Laboratories) |
| ORCA | Overarching Range Cooperative Agreement |
| ORCA | Ohio Romanian Children's Association |
| ORCA | Orlando Reef Caretakers Association (Florida) |