Sakai Tadamichi (酒井忠宝, July 14, 1856 – September 17, 1921) was the 12th (and final) daimyō of Shōnai Domain during Bakumatsu period Japan.

He became daimyō in 1868, when his elder brother, the 11th daimyō of Shōnai Sakai Tadazumi was deposed by the Meiji government over his role in leading the domain during the Boshin War as part of the pro-Tokugawa Ōuetsu Reppan Dōmei.

Shōnai Domain was initially punished by a reduction in kokudaka to 120,000 koku; however, the Meiji government was in a state of confusion and flux.

From 1868 to 1869, Sakai Tadamichi was also appointed ruler of Aizu Domain, which had been seized from the Aizu-Matsudaira clan.

Tokyo: Librarie Sansaisha...Click link for digitized 1906 Nobiliaire du japon (2003) 歴史群像編集部 (2010).