| Acronym | Definition |
|---|
| RTU | Rajasthan Technical University (India) |
| RTU | Remote Terminal Unit |
| RTU | Ready to Use |
| RTU | Registro Tributario Unificado (Spanish: Unified Tax Registry; Guatemala) |
| RTU | Right-To-Use |
| RTU | Right to Use |
| RTU | Radio Terminal Unit |
| RTU | Route Table Update |
| RTU | Riga Technical University |
| RTU | Remote Telemetry Unit |
| RTU | Roof Top Unit (ventilation or broadband networking component) |
| RTU | Replacement Training Unit |
| RTU | Remote Test Unit (Bellcore) |
| RTU | Radio Tuning Unit |
| RTU | Returned To Unit (military) |
| RTU | Routing Table Update (computing) |
| RTU | Real-Time Ultrasound |
| RTU | Rizal Technological University (Mandaluyong City, Metro Manila, Philippines) |
| RTU | Real Time UNIX (Concurrent Computer) |
| RTU | Residential Treatment Unit (corrections facility) |
| RTU | Remote Termination Unit |
| RTU | Real Time Unit |
| RTU | Radio Trait d'Union (French radio station) |
| RTU | Retail Tenancy Unit |
| RTU | Remote Transmission Unit (Sprint) |
| RTU | Reinforcement Training Unit |
| RTU | Remote Trunking Unit |
| RTU | Radio Telemetry Unit |
| RTU | Receiver/Transmitter Unit |
| RTU | Recruit Training Unit |
| RTU | Radio Test Unit |
| RTU | Radio Transmission Unit |
| RTU | Rock That Uke (movie) |
| RTU | Promotion of Reconciliation, Tolerance and Unity Bill (Fiji) |
| RTU | Reserve Training Unit |
| RTU | Remote Titration Unit |
| RTU | Readiness Training Unit |
| RTU | Radio Terminating Unit |
| RTU | Régulation du Trafic Urbain (French: Urban Traffic Control) |