The Matsudaira clan was a Japanese samurai clan that descended from the Minamoto clan. It originated in and took its name from Matsudaira village, in Mikawa Province. During the Sengoku period, the chieftain of the main line of the Matsudaira clan, Matsudaira Motoyasu became a powerful regional daimyo under Oda Nobunaga and Toyotomi Hideyoshi and changed his name to Tokugawa Ieyasu. He subsequently seized power as the first shōgun of the Tokugawa shogunate which ruled Japan during the Edo period until the Meiji Restoration of 1868. Under the Tokugawa shogunate, many cadet branches of the clan retained the Matsudaira surname, and numerous new branches were formed in the decades after Ieyasu. Some of those branches were also of daimyō status.

Mikawa Province was an old province in the area that today forms the eastern half of Aichi Prefecture. Its abbreviated form name was Sanshū . Mikawa bordered on Owari, Mino, Shinano, and Tōtōmi Provinces.