It is said that Oppo-ji Temple was founded by Gyoki Bosatsu and Baramon Sojo in the year 736 by the order of Emperor Shomu in order to pray for the tranquility of the Hokuriku area.
天平8年(736)に聖武天皇の勅命により行基菩薩、婆羅門僧正らが北陸一帯の安穏を祈り開山したと伝えられる。