Born in 1542 as heir to a local lord in Shima province. He emerged as the leader of the Shima naval forces (pirates) and entered Oda Nobunaga's service. On Nobunaga's orders he built Japan's first large ironclad warships, and at the Second Battle of Kizugawaguchi in 1578 he decisively defeated the Mori navy, cutting off supply lines to Ishiyama Honganji. These ironclads were a revolutionary weapon that transformed naval warfare. After Nobunaga's death he served Hideyoshi and commanded naval forces in Korea. At Sekigahara in 1600, the family was split—his son Morítaka joined the East while Yoshitaka joined the West. After defeat, Yoshitaka took his own life on Toshijima island off Toba at age 58, despite his son's frantic pleas for clemency.

Bold and innovative in thinking, he realized the unprecedented weapon of the ironclad warship. Though of pirate origin, he embodied Nobunaga's drive for technological innovation and was proactive in introducing new tactics and weapons.

The Battle of Kizugawaguchi using ironclad warships is recorded as a landmark in Japanese naval history. Kuki Yoshitaka is inscribed in Japanese maritime history as the "pirate daimyo," and historic sites related to him remain in Toba City, Mie Prefecture.