Tamura Yoshiaki served as a bushō and sengoku daimyō in Mutsu Province during the late Muromachi and Sengoku periods. Yoshiaki was the twenty-third head of the Tamura clan.
In 1487, Yoshiaki was born as the lineal heir of Tamura Moriaki. Yoshiaki was the older brother of Tamura Akiyori.
He wed as his formal wife the daughter of Iwaki Tsunetaka. Initially, Yoshiaki was based in Moriyama Castle, but, in 1504, built and moved to Miharu Castle.
Yoshiaki is responsible for establishing the foundation for the future prosperity of the Tamura clan.
In 1532, he transferred the headship of the clan to his eldest son, Tamura Takaaki, and retired.