Onøya[1] is an island in Lurøy Municipality in Nordland county, Norway.

The administrative centre of Lurøy Municipality is located on the northwestern coast of the island.

The island is connected to Lurøya by a short bridge.

Onøya sits just west of the mouth of the Sjona fjord.

The highest point on the island is the 197-metre (646 ft) tall mountain Stokksvikfjellet.