Britain's Lost Masterpieces is a factual BBC Four documentary television series that aims to uncover overlooked art treasures in British public collections, in conjunction with Art UK. It is presented by Bendor Grosvenor, along with art historian Jacky Klein and Emma Dabiri. The series also features the art restoration work of Simon Gillespie. In North American syndication, the series is called The Art Detectives.

Art UK is a cultural, education charity in the United Kingdom, previously known as the Public Catalogue Foundation. Since 2003, it has digitised more than 300,000 paintings, sculptures and other artworks by more than 53,700 artists.