THD may refer to: Total harmonic distortion, a measure of the distortion of an audio signal Total Hi Def (Total HD), an optical disc format Th.D. or D.Th. or D.Theol., a Doctor of Theology degree Thames Ditton railway station, Surrey, National Rail station code THD Electronics, a guitar amplifier manufacturer Transanal hemorrhoidal dearterialization, a surgical procedure That Handsome Devil, an American alternative rock band The IATA airport code for Thọ Xuân Airport The ICAO airline code for Thai Smile Transmitting Heading Device