Ezo (蝦夷), also known as Yezo or Yeso, is an ancient Japanese name for the lands to the north of Japan. It was the name of the northern Japanese island of Hokkaidō. It was also used as a name for islands in the Sea of Okhotsk, including the Kurile Islands and Sakhalin.
The terms Ezo, Yezo, Ebisu or Emishi were also used as a name for the people and culture of northern Honshu, including Akita Prefecture, Aomori Prefecture, Fukushima Prefecture, Iwate Prefecture, Miyagi Prefecture and Yamagata Prefecture.