St. Mary's Hospital, London

St Mary's Hospital is a hospital located in Paddington, London, England that was founded in 1845. Since the UK's first academic health science centre was created in 2008, it is operated by Imperial College Healthcare NHS Trust, which also operates Charing Cross Hospital, Hammersmith Hospital, Queen Charlotte's and Chelsea Hospital, Teddington Memorial Hospital and Western Eye Hospital; and runs some services at St Charles Hospital in Ladbroke Grove.

Until 1988 the hospital ran St Mary's Hospital Medical School, part of the federal University of London. In 1988 it merged with Imperial College London, and then with Charing Cross and Westminster Medical School in 1997 to form Imperial College School of Medicine. Imperial College left the federal university in 2007, to become independent.