The 7.2-square-kilometre (2.8 sq mi) island is home to almost all of the municipality's residents.
The island sits west of the Fedjefjorden, south of the mouth of the Fensfjorden, and north of the islands of Øygarden.
The North Sea lies to the west of the island.
The 47-metre (154 ft) tall Fedjebjørnen is the highest point on the mountain.
Hellisøy Lighthouse lies just off the southwestern coast of the island.