Mizuno Tadanori (水野忠敬, August 6, 1851 – August 18, 1907) was the 8th and final daimyō of Numazu Domain in Suruga Province, Honshū, Japan (modern-day Shizuoka Prefecture), and 15th hereditary head of the Numazu-Mizuno clan.

In 1867, he received the courtesy title of Dewa-no-kami and was appointed to the guard of the Otemon of Edo Castle.

However, the following year he pledged fealty to the new Meiji government and fought in the Boshin War against the remnants of the pro-Tokugawa forces.

he was appointed imperial governor of Kikuma until the abolition of the han system in 1871.

His wife was the third daughter of Ōkōchi Masatomo, daimyō of Ōtaki Domain