Shimazu Yoshihisa (島津義久, March 4, 1533 – March 5, 1611) was a daimyō of Satsuma Province and the eldest son of Shimazu Takahisa. His mother was a daughter of Iriki'in Shigesato (入来院重聡), Sesshō (雪窓). Shimazu Yoshihiro and Shimazu Toshihisa are his brothers.
His childhood name was Torajumaru (虎寿丸) but he went by the name of Matasaburō (又三郎). On his coming-of-age (genpuku), he took the name of Tadayoshi(忠良) but after receiving a kanji from the shōgun Ashikaga Yoshiteru, changed to Yoshitatsu (義辰). He later changed his name to Yoshihisa. He married his own aunt and after her death, married his relative, a daughter of Tanegashima Tokitaka.
In 1566, he succeeded his father as the head of Shimazu clan, becoming the clan's sixteenth leader. Working together with his brothers Yoshihiro, Toshihisa, and Shimazu Iehisa, he launched a campaign to unify Kyūshū. Starting in 1572 with the win against Itō clan at the battle of Kizaki, Yoshihisa would win victory after victory.
In 1578, he defeated the Ōtomo clan at the battle of Mimigawa, in 1583 against Ryūzōji clan, and on 1584 against the Aso clan. By the middle of the 1580s, the Shimazu clan controlled most of Kyūshū with the exception of Ōtomo's domain and a unification was not far into the future.
However, in 1587 Toyotomi Hideyoshi launched a campaign to pacify Kyūshū with an overwhelming force of over 200,000, at least five times the number under Yoshihisa's troops, and Shimazu troop was driven back to Satsuma province where they were forced to surrender. Most of domains they had conquered were divided by Hideyoshi and the Shimazu clan managed to retain only Satsuma Province and Ōsumi Province. Yoshihisa shaved his head to surrender showing that he would become a Buddhist monk if his life was spared. His name as a monk was Ryūhaku (龍伯) but it is unclear whether he retired to have Yoshihiro rule. As a retainer under Hideyoshi, his younger brother Yoshihiro controlled troops, but it is believed that Yoshihisa still managed day-to-day affairs in the domain. Yoshihisa did not have a son to succeed him, so he had Yoshihiro's son, Shimazu Tadatsune marry the third daughter Kameju (亀寿) and adopted him as the successor.
After Hideyoshi made decision on Yoshihisa's domain, Yoshihisa was invited by Tokugawa Ieyasu to Fushimi Castle. It is said that after asked repeatedly by Ieyasu and his retainers on how he almost unified Kyūshū, Yoshihisa finally relented and said "My three younger brothers led by Yoshihiro as well as retainers like Niiro Tadamoto fought so well united under the same goal, I never had a chance to show bravery in a battle. I only had to wait in the Kagoshima Castle for news brought by messengers of their victories." After Yoshihisa left, Ieyasu told his retainers that "(Yoshihisa had, as) a general let retainers under him work to the best of their abilities. This is how a great general should be."
He died of an illness in 1611. His posthumous name was 貫明存忠庵主. He was buried at what had once been the site of Fukushoji in Kagoshima and there is still a tombstone along with all other leaders of the clan. There are also monuments built in his memory at Kokubun city, Ima Kumano Kannonji (今熊野観音寺) in Kyoto, and Koyasan. There is no portrait of Yoshihisa remaining but in Taiheiji at Kawauchi, Kagoshima, there is a bronze figure of Yoshihisa of the surrender against Hideyoshi that was made after he died.
His knowledge of culture is not widely known but he had Hosokawa Yusai teach him classic literatures and Kampaku Konoe Wakihisa who was skilled in waka and renga was said to have frequented Yoshihisa's house.