真田氏
is a Japanese castle located in Ueda, northern Nagano Prefecture, Japan. At the end of the Edo period, Ueda Castle was home to a cadet branch of the Matsudaira clan, "daimyō" of Ueda Domain, but the castle is better known for its association with the Sengoku period Sanada clan. It was also called or . The castle was designated a National Historic Site of Japan in 1934.