| Acronym | Definition |
|---|
| OPUS | Online Processing User Service |
| OPUS | Optical Prism Uniformity System |
| OPUS | Optimized Power Usage Solution |
| OPUS | Online Positioning User Service |
| OPUS | Octal Program Updating System |
| OPUS | Olympic Properties of the US (joint marketing venture) |
| OPUS | Open Platform for Unregistered Securities (various companies) |
| OPUS | Organization for Paranormal Understanding and Support |
| OPUS | Organization of Persistent Upwelling Structures |
| OPUS | OSS-PODPS Unified System |
| OPUS | Open Process-Control Unified System |
| OPUS | Officer Planning and Utility System |
| OPUS | Online Personal Union Scheduling (Virtual Event Management Systems) |