GTR may refer to:
Transportation Great River Railroad, in Mississippi, US Grand Trunk Railway, a defunct North American railway Golden Triangle Regional Airport (IATA and FAA LID codes), serving Columbus, Mississippi, US Govia Thameslink Railway, a British railway operator Greater Thameslink Railway, Govia Thameslink Railway's nationalised successor GTR Euroseries, a short-lived European auto racing series Global Technical Regulations, a 1998 multinational agreement regarding vehicle regulations
Automobiles Gran Turismo (racing), a type of sports car BMW M3 GTR Holden Torana GTR Isuzu Bellett GT-R Mazda Familia GT-R McLaren F1 GTR McLaren P1 GTR McLaren Senna GTR Mercedes-AMG GT R Mercedes-Benz CLK GTR Nissan Skyline GT-R Nissan GT-R Porsche 718 GTR Coupe Prototype 1962 Porsche 924 Carrera GTR Toyota Celica 2000 GTR Ultima GTR Ford Mustang GT-R Concept car
Science and medicine General theory of relativity, also known as General relativity, in physics Generalised time reversible, in biology Guided tissue regeneration, in dentistry
Video games GTR – FIA GT Racing Game, a 2005 game GTR Evolution, a 2008 game GTR Group, owner of the developer Mad Catz
Other uses GTR (band), a British rock band GTR (album), their sole official studio album Gareth Emery, British trance producer and DJ Gateway to Research (Gtr), UK research information portal GTR-18 Smokey Sam, an American SAM training rocket Green tree reservoir, flooded forest land
See also GDR (disambiguation) GT (disambiguation) JTR (disambiguation)