TWI
- TW1 (disambiguation)
- TWL (disambiguation)
- Tailwind Airlines
- The Way International
- The Welding Institute
- Tin Wing stop
- Tolerable weekly intake
- Topographic Wetness Index
- Trade weighted index
- Training Within Industry
- Trans World International
- Twi
- Twi-
- Twickenham railway station
- Two-way immersion
- Two-wire interface