John Wills Greenslade (born Bellevue, Ohio, January 11, 1880, died January 6, 1950) was a Vice Admiral in the United States Navy. Admiral Greenslade enjoyed a significant military career during World War II. From 1941-1944 Greenslade was Commandant, Twelfth Naval District, with additional duty as Commandant, Pacific Southern Naval Coastal Frontier. On January 8, 1942, while he was serving at Mare Island Naval Shipyard, Greenslade urged that American-born and alien Japanese be excluded from areas of strategic importance. On April 17, 1942, the Navy seized Treasure Island, San Francisco, California from the City of San Francisco under the direction of Vice Admiral Greenslade, and paid no compensation for the confiscated island. Admiral Greenslade claimed Treasure Island was required for "nat