Terence Day (born 1940) is a musician specialising in free improvisation, a poet and a visual artist. He is a founding member of the Continuous Music Ensemble and The People Band. Some of his musical partners include
Derek Bailey,
Steve Beresford,
Phil Minton,
Evan Parker, Charlotte Hug,
John Russell, Rhodri Davis, Misha Mengelberg, Tony Oxley, Marten Altena, Phil Wachsman and John Tchicai. He is a member of the improvising quartet Alterations.