Banna-ji (鑁阿寺) is a Buddhist temple of the Shingon sect in the city of Ashikaga, Tochigi Prefecture, in northern Kantō region of Japan.

[1] The temple is built on the ruins of the ancestral fortified residence of the Ashikaga clan who ruled Japan during the Muromachi shogunate, and its grounds are a National Historic Site[2] Minamoto no Yoshiyasu was awarded a shōen (estate) in this area of Shimotsuke Province in the middle of the 12th century, and constructed a fortified residence.

The following year he installed a statue of Dainichi Nyōrai in his residence, transforming it into a Buddhist temple named Banna-ji.

However, by the Sengoku period, the power and influence of the Ashikaga clan had waned considerably, and the temple declined into near ruin.

The 40,000 square meter precincts of the temple gained protection as a National Historic Site in March 1922, and the main hall was designated as an Important Cultural Property of Japan in 1950.