Mizuno Tadayuki (?? ??, July 4, 1669 – April 23, 1731) was a Japanese daimyo of the Edo period.
He served in a variety of positions in the Tokugawa shogunate, including wakadoshiyori, roju, and Kyoto Shoshidai.
After the 47 ronin incident, Tadayuki was given custody of nine of the Ako men: Hazama Jujiro, Okada Suke'emon, Yato Emonshichi, Muramatsu Sandayu, Mase Magokuro, Kayano Wasuke, Yokogawa Sanpei, Muramatsu Jirozaemon, and Kanzaki Yogoro.