With an area of 18.3 km², Helgøya is the largest fresh-water island in Norway. The island is located south of the Nes peninsula, and has been connected to the mainland by the Nessundet Bridge since 1957.
The island consists of 32 farms. The most notable of these are the old manor Hovinsholm that until 1612 had its own church. Another old farm is Eik ('oak') that has given the name of the tallest hill on the island: Eksberget, and Høvelsrud which, with its 17th century gardens now open to the public, has recently been restored. The island is generally rich in medieval traces.
Helgøya Church (Helgøya kirke) was inaugurated on 7 December 1870. The chapel was built in timber and blockwork in the Gothic Revival style. The church has about 200 seats. The chapel was restored and partially rebuilt in the 1970s.
The Norse forms of the name were Helgøy and Øyin helga, both meaning 'holy island'. The farm name Hovin (Norse Hofvin - later named Hovinsholm, see above) on the southern tip of the island is a compound of hof n 'pagan temple (for the Norse gods)' and vin f 'meadow'.