The is a mountain range on the Bōsō Peninsula of Chiba Prefecture, Japan. The highest point in the Bōsō Mountain Range is at Mount Atago, with an altitude of . The hill range runs from roughly in a line from Mobara or Ōamishirasato to Kisarazu, but is not formally defined. It is an important part of the Minami Bōsō Quasi-National Park.