The Battle of the Santa Cruz Islands, fought during 25–27 October 1942, sometimes referred to as the Battle of Santa Cruz or Third Battle of Solomon Sea, in Japan as the Battle of the South Pacific , was the fourth aircraft carrier battle of the Pacific campaign of World War II. It was also the fourth major naval engagement fought between the United States Navy and the Imperial Japanese Navy during the lengthy and strategically important Guadalcanal campaign. As in the battles of the Coral Sea, Midway, and the Eastern Solomons, the ships of the two adversaries were rarely in sight or gun range of each other. Instead, almost all attacks by both sides were mounted by carrier- or land-based aircraft.
In an attempt to drive Allied forces from Guadalcanal and nearby islands and end the stalemate that had existed since September 1942, the Imperial Japanese Army planned a major ground offensive on Guadalcanal for 20–25 October 1942. In support of this offensive, and with the hope of engaging Allied naval forces, Japanese carriers and other large warships moved into a position near the southern Solomon Islands. From this location, the Japanese naval forces hoped to engage and decisively defeat any Allied (primarily U.S.) naval forces, especially carrier forces, that responded to the ground offensive. Allied naval forces also hoped to meet the Japanese naval forces in battle, with the same objectives of breaking the stalemate and decisively defeating their adversary.
The Japanese ground offensive on Guadalcanal was underway with the Battle for Henderson Field while the naval warships and aircraft from the two adversaries confronted each other on the morning of 26 October 1942, just north of the Santa Cruz Islands. After an exchange of carrier air attacks, Allied surface ships retreated from the battle area with the fleet carrier Hornet sunk, and another fleet carrier, Enterprise, heavily damaged. The participating Japanese carrier forces also retired because of high aircraft and aircrew losses, plus significant damage to the fleet carrier Shōkaku and the light carrier Zuihō.
Santa Cruz was a tactical victory and a short-term strategic victory for the Japanese in terms of ships sunk and damaged, and control of the seas around Guadalcanal. However, Japan’s loss of many irreplaceable veteran aircrews proved to be a long-term strategic advantage for the Allies, whose aircrew losses in the battle were relatively low and quickly replaced.