| Acronym | Definition |
|---|
| RTO | Registered Training Organisation (Australia) |
| RTO | Rent-To-Own |
| RTO | Recovery Time Objective (disaster recovery) |
| RTO | Retransmission Timeout |
| RTO | Regional Transmission Organization |
| RTO | Regenerative Thermal Oxidizer |
| RTO | Reverse Take-Over |
| RTO | Radio/Telephone Operator |
| RTO | Rejected Take-Off |
| RTO | Regional Transport Office |
| RTO | Rapid Thermal Oxidation |
| RTO | Research & Technology Organization |
| RTO | Return to Operations |
| RTO | Really Terrible Orchestra (Scottish amature orchestra) |
| RTO | Road Transport Office (India) |
| RTO | Responsible Test Organization |
| RTO | Returned to Owner (lost or stolen items) |
| RTO | Rapid Transit Operations |
| RTO | Real-Time Output |
| RTO | Registered Training Authority |
| RTO | Regional Transportation Organization |
| RTO | Remote Transcoder Operation |
| RTO | Recruit Training Officer |
| RTO | Return to Office (medical) |
| RTO | Ready to Order |
| RTO | Regimental Tactical Officer (United States Military Academy) |
| RTO | Radiation Therapy Oncology |
| RTO | Radio Transmission Operator |
| RTO | Railway Traffic Officer |
| RTO | Range Training Officer |
| RTO | Run-time object |
| RTO | Request to Order (purchasing) |
| RTO | Regional Trial Court (Philippines) |
| RTO | Request to Operate |
| RTO | Rail Transportation Officer |
| RTO | Request Time Off |
| RTO | Regional Training Office |
| RTO | Runners Team Omegna |
| RTO | Research and Training Organization |
| RTO | Roadranger, Twin Countershaft, Overdrive, (heavy truck transmission) |
| RTO | Reconnaissance Tasking Order |
| RTO | Regimental Training Officer |
| RTO | Report Time Over ... (location) |
| RTO | Release to Operations (date the project team no longer has primary responsibility) |
| RTO | Real Time Ownage |
| RTO | Return to Output |
| RTO | Return Timed Out |
| RTO | Residents Technical Office |
| RTO | Reverse Tool Order (wildland firefighting) |
| RTO | Representative Task Order (government contracting) |