Nishio Tadanao (西尾 忠移, 1749 – May 9, 1801) was a daimyō in mid-Edo period Japan, who ruled Yokosuka Domain in Tōtōmi Province.
Tadayuki entered the administration of the Tokugawa shogunate in 1784, holding the concurrent offices of Sōshaban and Jisha-bugyō.
There was a brief period where he was barred from service (after the burning of his Edo residence later that year), but he was soon back to work, and even retained his position despite the fact that his father-in-law was Tanuma Okitsugu.
In the administration of Yokosuka Domain, Tadayuki improved the financial situation by encouraging sweet potato cultivation and research into sugar refining.
He also had a great personal interest in the arts and in rangaku, and employed many prominent figures in this field, including Takamori Kankō.