Hōkoku Maru (報國丸) was an Hōkoku Maru-class ocean liner that served as an armed merchant cruiser in the Second World War. She was launched in 1939 and completed in 1940 for Osaka Shosen Lines. In 1941 she was commissioned into the Imperial Japanese Navy. She served as a commerce raider and submarine tender. Two Allied naval ships sank her in a naval engangement in 1942.