Gluck (Hannah Gluckstein, 13 August 1895 – 10 January 1978) was a British painter.
Gluck was born into a wealthy Jewish family, the child of Joseph Gluckstein, whose brothers Isidore and Montague had founded J. Lyons and Co., a British coffee house and catering empire. Gluck's American-born mother, Francesca Halle, was an opera singer. Her brother, Sir Louis Gluckstein, was a Conservative politician.
Gluck attended St John's Wood School of Art between 1913 and 1916 before moving to the west Cornwall valley of Lamorna and joining the artists' colony there. In the 1920s and 30s Gluck became known for portraits and floral paintings; the latter were favoured by the interior decorator Syrie Maugham. Gluck insisted on being known only as Gluck, "no prefix, suffix, or quotes", and when an art society of which she was vice president identified Gluck as "Miss Gluck" on its letterhead, Gluck resigned. Gluck identified with no artistic school or movement and showed her work only in solo exhibitions, where it was displayed in a special frame Gluck invented and patented. This Gluck-frame rose from the wall in three tiers; painted or papered to match the wall on which it hung, it made the artist's paintings look like part of the architecture of the room.
One of Gluck's best-known paintings, Medallion, is a dual portrait of Gluck and Gluck's lover, Nesta Obermer, inspired by a night in 1936 when she attended a Fritz Busch production of Mozart's Don Giovanni. According to Gluck's biographer Diana Souhami, "They sat together in the third row and felt the intensity of the music fused them both into one person and matched their love." Gluck referred to it as the "YouWe" picture. It was later used as the cover of a Virago Press edition of The Well of Loneliness. Gluck also had a romantic relationship with the British floral designer Constance Spry, whose work informed the artist's paintings.