The Treaty of Saint Petersburg (樺太・千島交換条約 Karafuto-Chishima Kōkan Jōyaku) (Russian:Петербургский договор) between the Empire of Japan and Empire of Russia was signed on 7 May 1875, and its ratifications exchanged at Tokyo on 22 August 1875.
Its terms stipulated that Japan cedes to Russia the part of Sakhalin island it then owned in exchange for the group of the Kuril Islands owned by Russia (between Iturup island and the Kamchatka Peninsula). Consequently, Sakhalin island as a whole became Russian territory, and the entire Kuril archipelago Japanese territory.
The authentic text of the Treaty is written in French. Differences with its Japanese translation contributed to the controversy on what constitutes the Kuril islands, claims to which Japan renounced in 1951 by the Treaty of San Francisco.
The Treaty of Shimoda of 1855 had defined the border between Japan and Russia to be the strait between Iturup (Etorofu) and Urup (Uruppu) islands in the Kurile chain, but had left the status of Sakhalin (Karafuto) open. Without well-defined borders, incidents between Russian and Japanese settlers began to occur. In order to remedy this situation, the Japanese government sent an ambassador, Enomoto Takeaki, to Saint Petersburg to clearly define the border in this area. After a year of negotiations, Japan agreed to renounce its claims to Sakhalin, with compensation for Japanese residents, access by the fishing fleet to the Sea of Okhotsk, ten-years free use of Russian ports in the area and ownership of all of the Kuril Islands.
- G. Patrick March (1996). Eastern Destiny: Russia in Asia and the North Pacific. Praeger/Greenwood. ISBN 0-275-95566-4.
- Tim Chapman (2001). Imperial Russia, 1801-1905. Routledge (UK). ISBN 0-415-23109-4.
- Thierry Mormanne (1992). "Le problème des Kouriles: pour un retour à Saint-Pétersbourg", in: Cipango, N° 1, Paris, p.58-89. ISSN 1164-5857.