JTB may refer to:
Jets to Brazil, an American rock band Johannes Thingnes Bø (born 1993), Norwegian biathlete John the Baptist (died circa 30), Jewish preacher and ascetic JTB (gene), a human gene Journal of Theoretical Biology, a scientific journal JTB Corporation, formerly Japan Travel Bureau, the largest travel agency in Japan Justified true belief, a philosophical definition of knowledge JTB (software), a preprocessor that produces JavaCC files Joint IED Defeat (JIEDD) Test Board, an organization within the Joint Improvised Explosive Device Defeat Organization J. Turner Butler Boulevard, a major expressway in Jacksonville, Florida carrying the designation Florida State Road 202