The Mahan-class destroyers of the United States Navy were 18 destroyers commissioned in 1936 and 1937. Two of these, Dunlap and Fanning, are sometimes considered as a separate ship class. Mahan was the lead ship, named for Rear Admiral Alfred T. Mahan, an influential historian and theorist on sea power.
The Mahans featured improvements over previous destroyers, with 12 torpedo tubes, superimposed gun shelters, and generators for emergency use. Ship displacement increased from 1,365 tons to 1,500 tons. The class introduced a new steam propulsion system that combined increases in pressure and temperature with a new type of lightweight steam turbine, proving simpler and more efficient than the Mahans' predecessors—so much so that it was used on many subsequent wartime US destroyers.
All 18 ships saw action in World War II, entirely in the Pacific Theater, including during the Guadalcanal Campaign, and the battles of the Santa Cruz Islands, Leyte Gulf, and Iwo Jima. Their participation in major and secondary campaigns included the bombardment of beachheads, amphibious landings, task force screening, convoy and patrol duty, and anti-aircraft and submarine warfare. Six ships were lost in combat and two were expended in the postwar Operation Crossroads nuclear tests. The remainder were decommissioned, sold, or scrapped after the war; none remain today. Collectively, the ships received 111 battle stars for their World War II service.