Ro-64, originally named Submarine No. 79, was an Imperial Japanese Navy Type L submarine of the L4 subclass. First commissioned in 1925, she served in the waters of Japan and Chōsen prior to World War II. During World War II, she operated in the Central Pacific, supported the Japanese invasion of Rabaul, and took part in the Aleutian Islands campaign, then in late 1942 was relegated to a role as a training ship. She was sunk in April 1945.