William Bruce Ellis Ranken (1881 – 31 March 1941) was a British artist and Edwardian aesthete.
He was born in Edinburgh, Scotland, to Robert Burt Ranken, a wealthy and successful lawyer, and his wife Mary.
He attended Eton College and then proceeded to the Slade School of Art, under the tutelage of Henry Tonks.
A fellow student was the actor Ernest Thesiger, who became a lifelong friend; he was painted by Ranken in 1918, and married Ranken's sister Janette Ranken in 1917.Ranken's first exhibition in 1904 at the Carfax Gallery (managed by John Fothergill and William Rothenstein) in London was well received by artists and art critics.
He befriended Wilfrid Gabriel de Glehn and John Singer Sargent.
At the outbreak of World War I, Ranken was living at his studio in Chelsea, a short distance from Sargent's studio, with whom he may have ventured to America during the war years.