TGA may refer to:
- The IATA Airport Code for Tengah Air Base, Singapore
- Tandy Graphics Adapter for the Tandy 1000 computer system
- Tasman Global Access, a submarine cable linking Australia and New Zealand
- Tennessee Governor's Academy for Math and Science, United States
- Therapeutic Goods Administration, Australian regulatory body
- Thermogravimetric analysis, materials testing procedure
- Thioglycolic acid, organic compound
- Tooronga railway station, Melbourne
- Transient global amnesia, a medical condition
- Transposition of the great arteries, a congenital heart defect
- Treasury General Account, a bank account held by the US government
- Truevision TGA or TARGA, graphics file format
- Tonga (IOC country code)
- TGA, one of three stop codons
- The Game Awards, annual awards ceremony for the video game industry
- The Gainsborough Academy, a school