| Acronym | Definition |
|---|
| TIO | Transfer in Order |
| TIO | Telecommunications Industry Ombudsman (Australia) |
| TIO | TMT (Thirty Meter Telescope) International Observatory, LLC (Pasadena, CA) |
| TIO | Test Input Output |
| TIO | Three in One |
| TIO | Tivoli Intelligent Orchestrator |
| TIO | Terminal Input Output |
| TIO | Turn It Off |
| TIO | Times of India |
| TIO | The Imperial Order (gaming) |
| TIO | Technology Innovation Office |
| TIO | Territory Insurance Office (Australia) |
| TIO | The Immovable Object |
| TIO | Take It Off |
| TIO | Technical Information Officer |
| TIO | Target Indication Officer (US Navy) |
| TIO | Tropical Intraseasonal Oscillation |
| TIO | Television Information Office |
| TIO | Target Information Officer |
| TIO | Time Interval Optimization |
| TIO | Technology Insertion Office |
| TIO | Training Integration Office |
| TIO | Testing, Inspection and Observation |