Okutono Domain , also known as Okudono, was a feudal domain under the Tokugawa shogunate of Edo period Japan, located in Kamo District and Nukata Districts of Mikawa Province, and in Saku District, Shinano Province, Japan. The domain was also known as Ogyū Domain and later known as Tanoguchi Domain and Tatsuoka Domain . The ruling family was the Ogyū-Matsudaira clan.

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.