The abbreviation TTI can refer to:
- Techtronic Industries, an electrical and electronic manufacturer and trader in Hong Kong.
- Texas A&M Transportation Institute, a component unit of the Texas A&M University System that researches the safety and efficiency of vehicles, roadways, and related transportation issues
- Texas Tennessee Industries, now Igloo Products Corporation
- Transmission Time Interval, a parameter related to encapsulation of data from higher layers into frames for transmission
- Toyota Technological Institute, a university located in Nagoya, Japan
- Toyota Technological Institute at Chicago, a computer science research institute located in Chicago, Illinois, USA
- TTI, Inc., a distributor of electronics components
- a type of martial arts belt worn with a Dobok
- TTI Team Telecom International, Ltd., an Operations Support Systems (OSS) vendor
- Transfusion transmitted infection, a disease that can be spread by blood transfusion.
- Trail Trace Identifier, an identifying string in the overhead of TDM-transmission.
- Time Temperature Indicator, a label/device that is shipped with food or pharmaceutical products and to indicate exposure to temperature variation.
- Travel Technology Interactive, a company in the airline industry.
- Tilted Transverse Isotropy, a type of Transverse isotropy.
- Turbo Technologies Incorporated, manufacturer of the TurboDuo