Håøya is an island in Oslofjorden in Frogn municipality, Norway. Its area is 5.6 km², which makes it the largest island in Inner Oslo Fjord.[1] It is located between Oscarsborg and Gråøya.
Søndre Håøya is a nature reserve area. White-tailed eagles nest on the southeastern part of the island. They returned in 2008 after an absence of 126 years.[2] Visitors are permitted to harvest mushrooms and berries under 'freedom to roam' but other plants and flowers are protected. Goats graze the island during the summer.
The island has a mooring jetty, camping areas, swimming beaches, public toilets, cabins for rent, and historic bunkers and buildings. The island was part of the defense of Oslo, along with Oscarsborg Fortress.
59°41′49″N 10°34′09″E / 59.6969°N 10.5692°E