Osterøy is an island situated northeast of the city of Bergen in Hordaland county, Norway. With a total area of , it is the largest Norwegian island not located directly adjacent to the ocean, and the second largest such island in Northern Europe. Osterøy is covered by two municipalities: the majority by Osterøy municipality, and the rest by Vaksdal municipality. The vast majority of the island's population lives in Osterøy municipality (7,305 inhabitants as of 2008).