William Lane Ewing (March 16, 1843 – June 4, 1905) was the 25th mayor of St. Louis, Missouri, serving from 1881 to 1885. Ewing helped organize the State National Bank in 1885 and was a member of its board of directors. During his administration the cable car was introduced to the city, 12 miles of business streets were paved, and the St. Louis Exposition and Music Hall was constructed (1884).