| Acronym | Definition |
|---|
| ROO | Kangaroo (short form) |
| ROO | Refined Olive Oil |
| ROO | Rules of Origin |
| ROO | Rub One Out |
| ROO | Right of Occupancy (legal right; various locations) |
| ROO | Read Only Operand |
| ROO | Royal Oak Offshore (watch) |
| ROO | Renewables Obligation Order (UK) |
| ROO | Return on Objective |
| ROO | Rules Of Order |
| ROO | Real Object Oriented (computer programming) |
| ROO | Return On Opportunity |
| ROO | Recruiting Operations Officer (US Army Cadet Command) |
| ROO | Regional Outreach Officer (Australia immigration) |
| ROO | Richland Operations Office |
| ROO | Record of Origin (Intel) |
| ROO | Reserve Officer Orientation |
| ROO | Research Opportunities Office (various schools) |
| ROO | Rail Ordnance Officer (Australia) |