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