William Muir Urquhart (December 22, 1855 – April 14, 1933) was an American entrepreneur, businessman, and public servant. For many years he was treasurer of Lewis County, Washington. He also served as mayor, councilman, and postmaster of Chehalis, Washington, where he lived and worked for more than fifty years. He was a merchant, banker, railroad entrepreneur, land developer and timber company investor. He was instrumental in planning the layout the business district of Chehalis in the early days of the city.