Langøya[1][2] is an island in Sandefjord Municipality in Vestfold county, Norway.

The 1.5-kilometre (0.93 mi) long island has an area of 550 decares (0.55 km2; 140 acres).

It is known for its wide variety of rare wildflowers including species such as sea thrift, alternate-leaved golden-saxifrage, cowslip, greater yellow-rattle, sticky catchfly, and many others.

[4] Five burial mounds from the Bronze Age have been discovered on the island.

[5] Historically, the island had been a part of Sandeherred and Stokke municipalities.