Duncan Grant (Duncan James Corrowr Grant, 21 January 1885 – 8 May 1978) was a British painter and designer of textiles, potterty and theatre sets and costumes. He was a member of the Bloomsbury Group.
He was a grandson of Sir John Peter Grant, 12th Laird of Rothiemurchus, and the first cousin twice removed of John Grant, Lord Huntingtower, heir of the Earls of Dysart.
Grant was born on 21 January 1885 in Rothiemurchus in northern Scotland. He studied art at the Slade School and in Italy and Paris. He was a cousin, and for some time a lover, of Lytton Strachey. Through the Stracheys, Duncan was introduced to the Bloomsbury Group, where John Maynard Keynes became another of his lovers.
From 1916 onwards Grant lived with the painter Vanessa Bell at Charleston Farmhouse in Sussex.