Akizuki Tanenaga (秋月 種長, March 17, 1567 – July 19, 1614) was a Japanese samurai warrior and daimyō of the late Sengoku and early Edo periods.
In 1586, Tanenaga joined with his father to fight against Toyotomi Hideyoshi forces during the Kyūshū campaign In 1598, Tanenaga made contributions at the Siege of Ulsan castle against the allied Chinese and Korean armies.
During the Korean campaign, Tanenaga served under Kuroda Nagamasa.
In 1600, in the Battle of Sekigahara, Tanenaga defended Ōgaki Castle on behalf of the "Western Army".
Tokugawa Ieyasu rewarded Tanenaga by recognizing his territory and enabling him to become the first head of Takanabe Domain in Hyūga Province on the island of Kyushu.