Karafuto Prefecture (樺太庁, Karafuto-chō; Japanese pronunciation: [ka.ɾa.ɸɯ̥.to]) was established by the Empire of Japan in 1907 to govern the southern part of Sakhalin. This territory became part of the Empire of Japan in 1905 after the Russo-Japanese War, when the portion of Sakhalin south of 50°N was ceded by the Russian Empire under the Treaty of Portsmouth.
Karafuto Prefecture was established in 1907 to govern Karafuto, which was part of Japan's External Land (Gaichi), until it was incorporated into an Inner Land (Naichi) of the Japanese metropole in April 1943. Ōtomari (Korsakov) was the capital of Karafuto from 1905 to 1908 and Toyohara (Yuzhno-Sakhalinsk) from 1908 to 1945.