Seshū Shinnōke

thumb|200px|Imperial Seal of Japan

was the collective name for the four cadet branches of the Imperial House of Japan, which were until 1947 entitled to provide a successor to the Chrysanthemum Throne if the main line failed to produce an heir. The heads of these royal houses held the title of , regardless of their genealogical distance from the reigning Emperor of Japan, as the term seshū in their designation meant that they were eligible for succession.