TGA may refer to:
- Thalamogeniculate artery, intracranial artery in human anatomy
- Thermogravimetric Analysis, materials testing procedure
- Truevision TGA, Truevision Graphics Adapter, compressed texture art file, with file extension
.tga - Therapeutic Goods Administration, Australian regulatory body
- Transient global amnesia, a medical condition
- Transposition of the Great Arteries, sub-group of congenital heart defects
- The Gaslight Anthem, American rock band
- Thioglycolic acid, organic compound
- Tonga (IOC country code)
- Tandy Graphics Adapter for the Tandy 1000 computer system.
- Top Gear Australia, motoring television series
- Tennessee Governor's Academy for Math and Science, United States
- The Gersh Agency, American talent agency
- The Glasgow Academy, Scotland, UK
- .tga, Truevision raster graphics file format
- One of three stop codons