| STTS | Safe Transportation Training Specialists 
| Others |
| STTS | Sano Thimi Technical School
| Others |
| STTS | Satguru Travel and Tours Services
| Others |
| STTS | Sekolah Tinggi Teknik Surabaya
| Others |
| STTS | Service To The Subscriber
| Others |
| STTS | Shatin Tsung Tsin School
| Others |
| STTS | Short Term Technology Solution
| Others |
| STTS | Simple Tree Transformation Sheets
| Others |
| STTS | Smile Through The S***
| Others |
| STTS | Smoother Than The Smoothest
| Others |
| STTS | Soft Tactile Transducer Sensor
| Others |
| STTS | Solomia Treshchuk Tax Services
| Others |
| STTS | Specialist Tactical Training Solutions
| Others |
| STTS | Speech to Text and Text to Speech
| Others |
| STTS | Speech to Text Text to Speech
| Others |
| STTS | Standardised Transfer Test Score
| Others |
| STTS | Stillaguamish Tribal Transit Services
| Others |
| STTS | Stillaguamish Tribe Transit Service
| Others |
| STTS | Strategic Timber Transport Scheme
| Others |
| STTS | Stronger than the Storm
| Others |
| STTS | Study Team and Teaching Strategies
| Others |
| STTS | Stuttgart Tubingen Tag Set
| Others |
| STTS | Stuttgart Tubingen TagSet STTS
| Others |