Katō Hiroharu, alternatively named Katō Kanji, was a Japanese naval officer during the Russo-Japanese War and World War I. The first name 'Kanji' was used in his later life after he became famous, likely just before he was promoted to rear-admiral. He served as the Chief of Navy General Staff from 22 January 1929 to 11 June 1930.

The Imperial Japanese Navy General Staff was the highest organ within the Imperial Japanese Navy. In charge of planning and operations, it was headed by an Admiral headquartered in Tokyo.