William Franklin Dunbar (November 8, 1820 – April 28, 1890) was an American politician. Born in Westerly, Rhode Island, he moved to Caledonia, Minnesota in 1854 and was a farmer. He served in the Minnesota Territorial House of Representatives in 1856-1857. From 1858-1861, Dunbar served as the first Minnesota State Auditor. Dunbar died on April 28, 1890. He is buried in Evergreen Cemetery in Houston, Minnesota.