Björn is an island in the north of the Swedish sector of the Bay of Bothnia, in the Kalix archipelago, the centre of a nature reserve of the same name.

[2] There are traces of an abandoned fishing village on the southwest of the island, with the foundations of two houses, and an ancient maze to the east.

[3] In 1969 the nearby wooded islets of the Björnrevet reef were declared a bird sanctuary.

In 1997 Björn and the smaller islets of Björnrevet, Björngrundet and Malgrundet were made a state-owned nature reserve, the furthest east in the Kalix archipelago.

The Björnrevet islets are partly covered in deciduous forest, set aside as a bird sanctuary in 1969.