GTO may refer to:
Entertainment Great Teacher Onizuka, a manga, anime, live-action series, and film GameTable Online, a game portal
Music bands GTO (band), an Australian band The GTOs, an American girl group Giraffe Tongue Orchestra, an American band Greater Than One, an English electronic music band
Other music uses GTO: Gangsters Takin' Over, an album by Oran "Juice" Jones GTO Records, a British record label "GTO" (Ronny & the Daytonas song), 1964 "GTO" (Sinitta song), 1987 "GTO", a 2017 song by Europe from the album Walk the Earth
Science and technology Gate turn-off thyristor Gaussian-type orbital Geostationary transfer orbit Golgi tendon organ
Transport Gorton railway station, in Greater Manchester, England Jalaluddin Airport (IATA: GTO) in Gorontalo, Indonesia Grand Touring Over, a category for production cars Gran Turismo Omologata, a model name of several grand tourer automobiles: Ferrari 250 GTO Ferrari 288 GTO Ferrari 599 GTO Pontiac GTO Mitsubishi 3000GT (Mitsubishi GTO in Japan) Mitsubishi Galant GTO HSV GTO
Other uses Geographic targeting order issued by the United States Secretary of Treasury Guanajuato, Mexico Ready for Labour and Defence of the USSR (Russian: , Gotov k trudu i oborone SSSR), a Soviet physical training programme Game theory optimal — poker strategy calculation