USS Hancock (CV/CVA-19) was one of 24 Essex-class aircraft carriers built during World War II for the United States Navy. Hancock was the fourth US Navy ship to bear the namesake of Founding Father John Hancock, president of the Second Continental Congress and first governor of the Commonwealth of Massachusetts. Hancock was commissioned in April 1944 and served in several campaigns in the Pacific Theater of Operations, earning four battle stars. Decommissioned shortly after the end of the war, she was modernized and recommissioned in the early 1950s as an attack carrier (CVA). In her second career, she operated exclusively in the Pacific, playing a prominent role in the Vietnam War, for which she earned a Navy Unit Commendation. She was the first US Navy carrier to have steam catapults installed. She was decommissioned in early 1976 and sold for scrap later that year.

The Essex class is a retired class of aircraft carriers of the United States Navy. The 20th century's most numerous class of capital ship, the class consisted of 24 vessels, which came in "short-hull" and "long-hull" versions. Thirty-two ships were ordered, but as World War II wound down, six were canceled before construction, and two were canceled after construction had begun. Fourteen saw combat during World War II. None were lost to enemy action, though several sustained crippling damage due to kamikaze attacks. Essex-class carriers were the backbone of the U.S. Navy from mid-1943 and, with the three Midway-class carriers added just after the war, continued to be the heart of U.S. naval strength until supercarriers joined the fleet in the 1950s, 1960s and 1970s. Several of the carriers were rebuilt to handle heavier and faster aircraft of the early jet age, and some served until well after the Vietnam War. Of the 24 ships in the class, four of the carriers: Yorktown, Hornet, Lexington, and Intrepid, have been preserved as museum ships.