USS Navajo III (SP-298), later USS SP-298, was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1919. Navajo III was built as a civilian motorboat of the same name in 1916 by the Gas Engine and Power Company and at Morris Heights in the Bronx, New York. The U.S. Navy acquired her for World War I service as a patrol vessel from her owner, Arthur Clapp, on 25 June 1917 and commissioned her the same day as USS Navajo III (SP-298) at the New York Navy Yard at Brooklyn, New York.