| Acronym | Definition |
|---|
| TSO | Time Sharing Option |
| TSO | Telecommunications Service Order |
| TSO | The Stationery Office (UK) |
| TSO | Trans-Siberian Orchestra (band) |
| TSO | Transportation Security Officer |
| TSO | Toronto Symphony Orchestra (Canada) |
| TSO | Technical Standard Order |
| TSO | Trattamento Sanitario Obbligatorio (Italian: Compulsory Health Treatment) |
| TSO | Technical Support Organization (various organizations) |
| TSO | Tokyo Symphony Orchestra (Japan) |
| TSO | The Sims Online (gaming) |
| TSO | Toledo Symphony Orchestra (Toledo, OH) |
| TSO | Tcp Segmentation Offload |
| TSO | Tasmanian Symphony Orchestra |
| TSO | Transmission System Operator (energy) |
| TSO | Teamspeak Overlay (gaming) |
| TSO | Texas State Optical (Houston, Texas) |
| TSO | The Sith Order (Roblox) |
| TSO | Technisch Secundair Onderwijs (Dutch) |
| TSO | Time Schedule Order (various locations) |
| TSO | The Shadow Odyssey (gaming; EverQuest) |
| TSO | Time Since Overhaul |
| TSO | Telecommunications Service Obligations (New Zealand) |
| TSO | The Special One (nickname of Jose Mourinho) |
| TSO | Trading Standards Officer |
| TSO | Temporary Suspension Order (various locations) |
| TSO | Technical Support Office |
| TSO | Total Shares Outstanding |
| TSO | Trondheim Symphony Orchestra (Norway) |
| TSO | Trichuris Suis Ova (pig whipworm eggs) |
| TSO | Total Store Ordering (SPARC architecture consistency model) |
| TSO | Taipei Symphony Orchestra (Taiwan) |
| TSO | Technical Service Order |
| TSO | Technical Services Operations |
| TSO | Turn Stuff Off (energy conservation campaign; US DoD) |
| TSO | The Smarter One |
| TSO | TCP (Transmission Control Protocol) Segmentation Offload (computer networking) |
| TSO | The Speakeasy Offensive (Counter-Strke team) |
| TSO | Tempe Symphony Orchestra (Tempe, AZ) |
| TSO | Time Stamp Ordered |
| TSO | Tactical Sensor Operator (military aviation) |
| TSO | Technical Staff Officer |
| TSO | Tight Shut Off (emergency system valve feature) |
| TSO | Trial Services Office (US military) |
| TSO | Terminal Security Officer |
| TSO | Third Sector Organization (non-profit) |
| TSO | Tactical Systems Officer |
| TSO | Transfer Student Ombudsperson (Maricopa County, AZ community college system) |
| TSO | Technology Spillovers |
| TSO | Temporary Standing Order (US DoD) |
| TSO | Temporary Slow Order (railway) |
| TSO | Transportation Supply Officer |
| TSO | Town Sub-Office |
| TSO | Tactical Support Operations |
| TSO | Thru-Short-Open |
| TSO | Telephone Service Observation |
| TSO | Transmission Systems Operations/Operator (telecommunications) |
| TSO | Test Support Office |
| TSO | Timberline Symphony Orchestra (Lafayette, CO) |
| TSO | Transaction Server Operation |