Ruth "Ester" Elisabet Ellqvist (4 October 1880 – 20 November 1918) was a Swedish artist, model and wife of John Bauer, who was a painter and illustrator. She studied at the Royal Swedish Academy of Arts and spent one year studying art in southern Germany and Italy with her husband. She died in 1918 with her husband and three-year-old son when the boat that they sailed on sank, killing all 24 people on board.