TMG could refer to:
In science and technology:
- Tensiomyography, a novel method for skeletal muscles' contractile parameters detection
- Trimethylglycine, a chemical compound studied in biochemistry
- Trimethylgallium, a chemical compound used in semiconductor fabrication
- Touring Motor Glider, a term used in aviation
- Thermal Micrometeoroid Garment, the outer layer of a space suit
- Thermomechanical generator, a Stirling engine invented by Cooke-Yarborough
- Threat Management Gateway, a software-based firewall solution, the member of Microsoft's Forefront product family, the successor of the Internet Security and Acceleration Server
- 1,1,3,3-Tetramethylguanidine, a chemical compound
In music:
- KTMG, a commercial radio station in Prescott, Arizona, United States
- WTMG, a commercial radio station in Williston, Florida, United States
- Ted Mulry Gang, an Australian rock group
- The Militia Group, a record label
- The Mountain Goats, a folk rock band
- Tak Matsumoto Group, a Japanese supergroup
In computing:
- TMG (programming language), an early compiler definition language and parser generator
- Microsoft Forefront Threat Management Gateway, a firewall and security software
- The Master Genealogist, a genealogy software
In other media:
- Trader Media Group, a publishing company based in the United Kingdom
- Telegraaf Media Groep, a Dutch media and publishing company
- The McLaughlin Group, a weekly public affairs show created by John McLaughlin
- Terror of Mechagodzilla, a 1975 science fiction film directed by Ishiro Honda
Other uses:
- TMG, Tunney Media Group, the fictional company that owns NBS on Studio 60 on the Sunset Strip
- Tennessee Meiji Gakuin High School
- Tokyo Metropolitan Government, the prefectural government of Tokyo
- TMG, the NYSE symbol for oil pipeline and terminal company TransMontaigne
- Tunisia Monitoring Group, a coalition of 16 free expression organisations
- Toyota Motorsport GmbH, a company based in Cologne, Germany