Matsudaira Tadaaki (松平 忠明) was a Japanese samurai and the 9th head of the Matsudaira clan. He lived during the late Edo period and was known for his role as a feudal lord in the Mikawa Province. Tadaaki was recognized for his leadership and contributions to the governance of his domain. He was born in 1790 and passed away in 1856. Tadaaki was also involved in the political changes leading up to the Meiji Restoration, a significant period that transformed Japan from a feudal society into a modern state. His legacy is part of the broader history of the samurai class in Japan.