The 138-square-kilometre (53 sq mi) island lies off the west coast of the mainland of Helgeland, Norway.

The northern and central parts of the island are low and relatively flat, partly marshy which nice coastal beaches.

The highest point on the island was the 858-metre (2,815 ft) tall mountain Dønnamannen in the south part of the island.

[2] The island is only connected to the mainland by ferry connections with the nearby town of Sandnessjøen (and to the neighboring island of Løkta).

Dønna is connected to the island of Staulen (in Herøy Municipality) by the Åkviksundet Bridge on the southern tip of the island.