Thierre De Mey (born 28 February 1956 in Brussels) is a musician and filmmaker from Belgium.
After studying film at the Institut des Arts de Diffusion, he continued to studying music composition and contemporary dance after meeting Fernand Schirren, for whose works he has written original incidental music. He works primarily with Anne Teresa De Keersmaeker, Wim Vandekeybus and Michèle Anne De Mey, his youngest sister.

He is the founder of the contemporary music ensemble Maximalist!, and he has participated in other important projects such as Musique Nouvelles (fr) and Ictus Ensemble, for which he has composed several works. In 1993 he joined a class at IRCAM, where he developed his interest in electronic music. He was composer in residence at the Conservatory of Strasbourg and the Musica Festival in 2001 and 2002.

Since 2005 he has been one of four new directors of Charleroi / Danses, coordinating the multidisciplinary activities of the center choreography.