(1885–1966), US naval officer. Chief of the Bureau of Navigation (1939–41), he became commander in chief of the Pacific Fleet after the Japanese attack on Pearl Harbor in 1941. A noted strategist, he introduced the practice of island hopping, which contributed to many victories. Nimitz accepted the Japanese surrender for the US in 1945 aboard his flagship, the USS Missouri, and after World War II served as chief of naval operations 1945–47.