Hosokawa Takakuni (細川 高国, 1484 – 17 July 1531) was the most powerful military commander in the Muromachi period under Ashikaga Yoshiharu, the twelfth shōgun.
In 1508, when Ōuchi Yoshioki marched his armies into Kyoto with Ashikaga Yoshitane (the former shōgun who had escaped to Suō Province), Takakuni conspired with them and purged the shogun Ashikaga Yoshizumi and Sumimoto to Ōmi Province.
Takakuni took Yanagimoto Kataharu, the younger brother of Kozai Motomori, chief vassal of the Hosokawa people, as his wakashū and the two swore eternal love to each other.
Though initially appeased by his lord, Yanagimoto shortly after joined with another brother against the cousin to avenge Motomori's death.
In 1531, his army was defeated, and he hid in a store room for alcoholic beverage at Amagasaki, Settsu Province.