William D. McDowell (January 3, 1927 – April 13, 2007) was an American Republican Party politician who served as the first elected County Executive of Bergen County, New Jersey. McDowell served as a Mayor and Councilman in North Arlington, New Jersey, and on the Bergen County Board of Chosen Freeholders. He was appointed by Governor William T. Cahill to serve as the first Executive Director of the Hackensack Meadowlands Development Commission, and later served as the Bergen County Republican Chairman. He was elected Bergen County Sheriff in 1981 and re-elected in 1984.