| TTIS | Technology Training And Instructional Support 
| Others |
| TTIS | Technology Training/Integration Specialists
| Others |
| TTIS | Teens Teaching Internet Skills
| Others |
| TTIS | Texas Teratogen Information Service
| Others |
| TTIS | The Telegraph in Schools
| Others |
| TTIS | Titan Technologies Information Systems
| Others |
| TTIS | Total Time In Service
| Others |
| TTIS | Touching Things In Space
| Others |
| TTIS | Traffic And Travel Information Systems
| Others |
| TTIS | Training For The Individual Soldier
| Others |
| TTIS | Transkentucky Transportation Railroad
| Others |
| TTIS | Transkentucky Transportation Railroad Incorporated
| Others |
| TTIS | Trauma Training in Scotland
| Others |
| TTIS | Travel and Traffic Information System
| Others |
| TTIS | Travel and Transport Information Service
| Others |
| TTIS | Traveller & Tourist Information System
| Others |
| TTIS | Ts The Telegraph In Schools
| Others |