STI
- Cell (microprocessor)
- Cibao International Airport
- IF (x86 flag)
- List of airline codes (S)
- ST1 (disambiguation)
- STI College
- Sail Training International
- Sangha Theravada Indonesia
- Scottish Development International
- Sega Technical Institute
- Semantic Technology Institute International
- Sexually transmitted infection
- Shallow trench isolation
- Shimano Total Integration
- Shun Tin station
- Signal transduction inhibitor
- Soft tissue injury
- Speech transmission index
- Stationary target indication
- Stieng language
- Still Image Architecture
- Stirlingshire
- Straits Times Index
- Subaru Impreza WRX STI
- Subaru Tecnica International
- Symptom targeted intervention
- Verkehrsbetriebe STI