Operation Vengeance was the American military operation to kill Admiral Isoroku Yamamoto of the Imperial Japanese Navy on April 18, 1943, during the Solomon Islands campaign in the Pacific Theater of World War II. Yamamoto, commander of the Combined Fleet of the Imperial Japanese Navy, was killed on Bougainville Island when his transport bomber aircraft was shot down by United States Army Air Forces fighter aircraft operating from Kukum Field on Guadalcanal.

The mission of the U.S. aircraft was specifically to kill Yamamoto and was based on United States Navy intelligence on Yamamoto's itinerary in the Solomon Islands area. The death of Yamamoto reportedly damaged the morale of Japanese naval personnel, raised the morale of the Allied forces, and was intended as revenge by U.S. leaders, who blamed Yamamoto for the attack on Pearl Harbor that initiated the war between Imperial Japan and the United States.

The U.S. pilots claimed to have shot down three twin-engine bombers and two fighters during the mission, but Japanese records show only two bombers were shot down. There is a controversy over which pilot shot down Yamamoto's plane, but most modern historians credit Rex T. Barber.