It is located in the Meløyvær archipelago, consisting of 365 small islands, with over 20 white-sand beaches.

Krøttøy is surrounded by the large islands of Senja to the east, Bjarkøya and Grytøya to the south, and Andøya to the west.

The main attractions are Viking graves and the Meløyvær fortress which is a national museum.

The island was of great strategic importance during the Cold War thus holding back a possible naval attack of the Soviet Navy on the supply lines and defence positions of the Norwegian Army in Northern Norway.

It is connected daily by a catamaran operated by Boreal Transport with the islands of Bjarkøya and Senja and with the town of Harstad.