The Marriage of William Ashe is a novel by Mary Augusta Ward that was the best-selling novel in the United States in 1905. It originally appeared in serial form in Harper's Magazine from June 1904 through May 1905, and was published in book form in March 1905. Illustrations were provided by Albert Sterner. The novel is loosely based on the lives of statesman William Lamb Melbourne and his eccentric wife Lady Caroline Lamb.