Vallance was born at Paisley on 13 Feb. 1827, the youngest son in the family of six sons and one daughter of David Vallance, tobacco manufacturer, by his wife Margaret Warden. William, whose father died in William's childhood, was sent at a very early age to work in a weaver's sho ; but on the family's subsequent removal to Edinburgh he was apprenticed in 1841 as a carver and gilder to Messrs. Aitken Dott. During his apprenticeship he began to paint, and made a little money by drawing chalk-portraits ; but he was twenty-three before he received any proper instruction. He then worked for a short time in the Trustees' Academy under E. Dallas, and later, from 1855, studied under R. S. Lauder. Vallance waselected associate of the Royal Scottish Academy in 1875, and become an academician in 1881.