Björkö

Björkö (Swedish for "Birch Island") can signify:

1. In Sweden:
   1. Björkö, a Lake Mälaren island in Ekerö Municipality, Stockholm County, the location for the excavation and World Heritage Site Birka.
   2. Björkö, an island in Öckerö Municipality, Västra Götaland County.
   3. Björkö, an island in Haninge Municipality, Stockholm County.
   4. Björkö, the southern part of Väddö island in northern Roslagen, Norrtälje Municipality, Stockholm County. (Also a former parish there.)
   5. Björkö, an island in Västervik Municipality, Kalmar County.
2. In Finland:
   1. Björkö, one of the main islands of the former municipality Houtskär in the Archipelago Sea.
   2. Björkö, a Kvarken island in Korsholm Municipality, Ostrobothnia.
   3. Björkö, an island and a village in Kumlinge Municipality in the Åland Islands.
   4. Björkö, an island in the former municipality Korpo in the Archipelago Sea.
3. In Russia:
   1. The Swedish name for Primorsk and the Beryozovye Islands in the Leningrad Oblast,
   2. The Treaty of Björkö, signed by Nicholas II of Russia and William II of the German Empire in 1905.