The Battle of Empress Augusta Bay, on 1–2 November 1943 – also known as the Battle of Gazelle Bay, Operation Cherry Blossom, and in Japanese sources as the Sea Battle off Bougainville Island (ブーゲンビル島沖海戦) – was a naval battle fought near the island of Bougainville in Empress Augusta Bay. The naval battle was a result of Allied landings on nearby Bougainville in the first action in the Bougainville campaign of World War II and may also be considered as part of the Solomons and New Guinea campaigns. The battle was significant as part of a broader Allied strategy—known as Operation Cartwheel—aimed at isolating and surrounding the major Japanese base at Rabaul. The intention was to establish a beachhead on Bougainville, within which an airfield would be built.

The naval battle took place at the end of the first day of the landings around Cape Torokina, as the Japanese sortied a large force from Rabaul in an effort to replicate the success they had achieved at Savo Island in August 1942, in response to Allied amphibious landings in the eastern Solomon Islands. Ultimately, the covering force of US warships was able to turn back the Japanese force and the landings around Cape Torokina were successful.