Mizuno Tadamasa (水野 忠政, 1493 – 22 August 1543) was a Japanese samurai lord and daimyo of the Sengoku period.
He was the father of Odai no Kata, the mother of shōgun Tokugawa Ieyasu.
He was a member of the Mizuno clan.
In 1533, Mizuno Tadamasa built and ruled Kariya Castle.
[1] Tadamasa was the father of Mizuno Nobumoto and Mizuno Tadashige.