Mizuno Nobumoto (水野 信元, died January 27, 1576) was a daimyo of Japan's Sengoku period. A son of Mizuno Tadamasa, and brother of Mizuno Tadashige, he was the lord of Kariya Castle.
Nobumoto sided with Oda Nobuhide in 1542, having switched his allegiance from the Imagawa family, but soon changing sides once more, to serve under the Matsudaira family. He was assigned Kariya Castle to defend. Oda Nobunaga blamed Nobumoto of selling rice to Akiyama Nobutomo (a rival Takeda officer), in 1576. Tokugawa Ieyasu thus sent Hiraiwa Chikayoshi to kill him. Nobumoto's brother, Mizuno Tadashige then went on to take Nobutomo's place.
Nobumoto is buried in the Mizuno family temple, Ryogon-ji, a Zen Buddhist monastery established in 1413, in Kariya, Japan.