| OPUS | Oberlin Project for Unified Systems 
| Others |
| OPUS | Observations of Persistent Upwelling Systems
| Others |
| OPUS | Octal Program Updating System
| Others |
| OPUS | Offender Population United System
| Others |
| OPUS | Offering Perspective Using Storytelling
| Others |
| OPUS | Officer Program for Undergraduate Students
| Others |
| OPUS | Older People Up to Something
| Others |
| OPUS | One Point Universal System
| Others |
| OPUS | Online Pathway for University Students
| Others |
| OPUS | Online Payroll Update System
| Others |
| OPUS | Online Positioning User Service
| Others |
| OPUS | Online Processing User Service
| Others |
| OPUS | Online Publications University of Stuttgart
| Others |
| OPUS | Open Platform for Unlimited Signification
| Others |
| OPUS | Open Portal to University Scholarship
| Others |
| OPUS | Operation to Prevent Unwanted Species
| Others |
| OpUS | Operation United States
| Others |
| OPUS | Operational Pipeline Unified Systems
| Others |
| OPUS | Optical Prism Uniformity System
| Others |
| OPUS | Optimising Public Understanding of Science
| Others |
| OPUS | Optimized Power Usage Solution
| Others |
| OPUS | Organization for Paranormal Understanding and Support
| Others |
| OPUS | Oscillating Pick Up System
| Others |
| OPUS | Oscillating Pick-Up Ignition System
| Others |
| OPUS | OSS/PODPS (Observation Support System/Post-Observation Data Processing System) Unified System
| Others |
| OPUS | Outer Planet U Search
| Others |
| OPUS | Outstanding People United to Sing
| Others |