Kate Victoria "KT" Tunstall (born 23 June 1975, St Andrews, Fife, Scotland) is a Scottish singer-songwriter and guitarist. She broke into the public eye with a 2004 live solo performance of her song "Black Horse and the Cherry Tree" on Later... with Jools Holland. She has enjoyed commercial and critical success since, picking up three nominations before winning a BRIT Award, and a Grammy Award nomination. She is also the recipient of an Ivor Novello Award.

Tunstall has a contralto vocal range. She has released four albums internationally: Eye to the Telescope (2004), KT Tunstall's Acoustic Extravaganza (2006), Drastic Fantastic (2007) and Tiger Suit (2010).

She has also appeared in an episode (S1E04) of the comedy series This is Jinsy on BBC Three.