The Naval Battle of Hakodate was fought from 4 to 10 May 1869, between the remnants of the Tokugawa shogunate navy, consolidated into the armed forces of the rebel Ezo Republic, and the newly formed Imperial Japanese Navy. It was one of the last stages of Battle of Hakodate during the Boshin War, and occurred near Hakodate in the northern Japanese island of Hokkaidō.

The Republic of Ezo was a short-lived separatist state established in 1869 on the island of Ezo, now Hokkaido, by a part of the former military of the Tokugawa shogunate at the end of the Bakumatsu period in Japan. It was the first government to attempt to institute democracy in Japan, though voting was allowed only to the samurai caste. The Republic of Ezo existed for five months before being annexed by the newly established Empire of Japan.