Hankyu Sasaki (佐々木 半九, 1 January 1896 – 6 October 1971) was an Imperial Japanese Navy admiral.

During World War II he was force commander of the midget submarines that attacked Pearl Harbor and Sydney Harbour.

He attended Hiroshima Prefectural Tertiary High School and then joined Class 45 of the Japanese Naval Academy at Etajima on 24 November 1917.

[3] In October, Sasaki was assigned to Matsumura's I-21 in Sixth Fleet chief of staff, Rear Admiral Hisashi Mito's E-force.

Sasaki and Commander Torisu Kennosuke (鳥巣　建之助) developed the strategy for their training and use, primarily against ships at anchor.