Kuril Islands (Japanese Chishima-rettō, Russian Kuril'skiye Ostrova, from the word kurit,”to smoke”), chain of 56 large and small volcanic islands in far eastern Russia, separating the Sea of Okhotsk from the Pacific Ocean. The islands extend from northeastern Hokkaidō Island in Japan to southern Kamchatka Peninsula in Russia. The Kurils are heavily forested and contain many active volcanoes. Hunting, fishing, and sulfur mining are the chief occupations of the inhabitants. The Kurils were settled by both the Russians and Japanese in the 18th century.

In 1875 Japan ceded to Russia the nearby island of Sakhalin in exchange for full Japanese possession of the Kurils. The islands were returned to the Union of Soviet Socialist Republics (USSR) by an agreement reached at the Yalta Conference during World War II (1939-1945). After the war Japan maintained a claim to the southernmost islands, and the territorial dispute prohibited the countries from signing a peace treaty. In the early 1990s Japan increased diplomatic pressure for return of the disputed islands, which became a focus of contention between Russia and Japan. In the mid-1990s the two nations continued negotiations about the islands, while there were clashes between Russian patrol boats and Japanese fishing boats in the area. The Kurils are administered as part of Sakhalin Oblast, Russia. In 1994 an undersea earthquake measuring 7.9 on the Richter scale shook the islands, killing at least 16 people. The islands' area is 16,000 sq km (6,000 sq mi).