Björkö

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