TTA may refer to
- Tan Tan Airport - IATA code for Moroccan airport
- Teacher Training Agency - former name of the Training and Development Agency for Schools
- Telecommunications Technology Association in Korea
- Telefon Tel Aviv, an IDM band from the United States
- Tennessee Telecommunications Association, a telecommunications industry trade organization
- Tennessee Trails Association
- Terran Trade Authority, the setting for a series of science-fiction books
- Tetradecylthioacetic Acid, a fatty acid
- Texas Telephone Association, a trade association for telephone companies in Texas
- Thai Tiger Airways, a Thai low-fare airline
- The Tough Alliance, a synthpop duo from Sweden
- Tibial tuberosity advancement, a knee operation in dogs
- Tiny Toon Adventures
- Toledo Technology Academy
- Toon Toon Army, a chant about the supporters of Newcastle United
- Tomorrowland Transit Authority, a ride at Walt Disney World
- Touring Car Team Association, a Swedish touring car championship.
- Tramway Touristique de l'Aisne, a touristic tramway in Belgium
- Transport triggered architecture, a kind of CPU design
- Triangle Transit Authority, a regional transit service in North Carolina
- Tri-State Transit Authority, a transit service in the Huntington, West Virginia area
- TTA (codec), True Audio codec
- Transport Ticketing Authority, a division of the Department of Infrastructure in the State Government of Victoria, Australia.
- Twin Turbo Aftercooled
- TTA - Test Trend Analyzer, an opensource product to help those working in large organizations understand the health of their products / projects at a quick glance