| Acronym | Definition |
|---|
| RRU | Remote Radio Unit (telecommunications) |
| RRU | Royal Roads University (Victoria, British Columbia, Canada) |
| RRU | Rock Raiders United (Lego enthusiast group) |
| RRU | Règlement Régional d'Urbanisme (French: Regional Planning Regulations; Belgium) |
| RRU | Radio Remote Unit (antenna connection) |
| RRU | Radio Research Unit |
| RRU | Relief and Recovery Unit (UN) |
| RRU | Research/Recertify/Upgrade (security clearance) |
| RRU | Rural Regeneration Unit (UK) |
| RRU | Remington Rand UNIVAC |
| RRU | Reduced-Resolution Update |
| RRU | Request to Research/Upgrade (Joint Personnel Adjudication System) |
| RRU | Remote Reset Unit |
| RRU | Responsible Radiation User (McGill University; Montreal, Canada) |