MTT can refer to:
People Michael Tilson Thomas (1944–2026), American musician, conductor, pianist
Technology and science Meaning–text theory, a theory in linguistics MTT assay using dimethyl thiazolyl diphenyl tetrazolium salt, a type of tetrazole Multi-transaction translator, a particular functional unit in USB hubs
Business Maritime Telephone and Telegraph Company, later known as MTT or MT&T
Transport Metropolitan Transport Trust, transport authority in Western Australia from 1958 to 2003 Minatitlán/Coatzacoalcos National Airport, IATA code MTT Municipal Tramways Trust, former body in Adelaide, South Australia
Fiction Multi-troop transport vehicle in Star Wars Mettaton, a robot character from Undertale
Other Maria Theresa thaler, former Austrian coin used in many areas Pashtun Tahafuz Movement (PTM), formerly known as the Mehsud Tahafuz Tehrik (MTT), a human rights movement in Pakistan for the Pashtun people Multi-table tournament, a type of poker tournament Modus tollens, a kind of rule of inference also known as modus tollendo tollens