Radøy is a former municipality in the Nordhordland district of the old Hordaland county, Norway. The municipality existed from 1964 until its dissolution in 2020 when it was merged into the new municipality of Alver in Vestland county. The municipality included almost all of the island of Radøy plus many small surrounding islands. The administrative centre of the municipality was the village of Manger. Other villages in the municipality included Askeland, Austmarka, Bøvågen, Haugland, Sæbø, and Sletta.

Prior to its dissolution in 2020, the 111-square-kilometre (43 sq mi) municipality is the 372nd largest by area out of the 422 municipalities in Norway. Radøy is the 199th most populous municipality in Norway with a population of 5,128. The municipality's population density is 48 inhabitants per square kilometre (120/sq mi) and its population has increased by 10.1% over the last decade.

During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. Radøy was created as a new municipality on 1 January 1964. The new municipality was constructed from parts of several different municipalities:

• all of Manger Municipality (population: 1,344)
• all of Hordabø Municipality (population: 1,679)
• the island of Bognøy from Herdla Municipality (population: 29)
• most of Sæbø Municipality, except the Titland area on the Lindås peninsula (population: 916)
• the Sletta area on the island of Radøy from Lindås Municipality (population: 305)
• the Straume area on the island of Radøy and the small island of Fesøy from Austrheim Municipality (population: 56)

On 1 January 2020, the neighboring Meland Municipality, Radøy Municipality, and Lindås Municipality were merged into the new Alver Municipality.

The municipality is named after the island of Radøy (Old Norse: Rǫð) since the municipality encompassed the island. The first element is rǫð which means "row", "ridge", or "line" (here in the sense that it is a "long island" sticking out of the ocean). The last element, øy which means "island", was added later as a suffix to the name.

The coat of arms was granted on 14 June 1991 and it was in use until 1 January 2020 when the municipality was dissolved. The official blazon is "Or, two oarlocks in pale sable" (Norwegian: På gul grunn to svarte årekeipar.). This means the arms have a field (background) has a tincture of Or which means it is commonly colored yellow, but if it is made out of metal, then gold is used. The charge is a pair of oarlocks, one above the other. Oarlocks are on the gunwale of a boat and they support the oar and give force to the rower's stroke. Some of these objects have been found in several places in Radøy and the artifacts date back to the first century BC. The arms were designed by Even Jarl Skoglund. The municipal flag has the same design as the coat of arms.

The Church of Norway had one parish (sokn) within the municipality of Radøy. It is part of the Nordhordland prosti (deanery) in the Diocese of Bjørgvin.

Churches in Radøy

Parish (sokn)	Church name	Location of the church	Year built
Radøy	Hordabø Church	Bøvågen	1875
	Manger Church	Manger	1891
	Sæbø Church	Sæbø	1883
	Emigrant Church, Sletta	Sletta	1997

During its existence, this municipality was governed by a municipal council of directly elected representatives. The mayor was indirectly elected by a vote of the municipal council.

The municipal council (Kommunestyre) of Radøy was made up of 25 representatives that were elected to four year terms. The party breakdown of the final municipal council was as follows:

This list is incomplete; you can help by adding missing items. (June 2023)

The mayors (Nynorsk: ordførar) of Radøy (incomplete list):

• 1983–1990: Olav Marås
• 2003–2007: Olav Steinar Namtvedt (Sp)
• 2007–2019: Jon Askeland (Sp)

Historical population
Year	1964	1970	1980	1990	2000	2010	2019
Pop.	4,329	4,100	4,363	4,560	4,585	4,825	5,128
±% p.a.	—	−0.90%	+0.62%	+0.44%	+0.05%	+0.51%	+0.68%
Source: Statistics Norway

The municipality encompassed all of the island of Radøy, except the far southern tip (which belonged to Lindås municipality). The smaller surrounding islands of Toska, Bognøy, Fesøy, and others were also part of Radøy municipality. The Radfjorden separated Radøy municipality from the municipality of Meland to the south. The Radsundet strait separated the municipality of Radøy from the municipality of Lindås to the east. The island of Fosnøyna (in Austrheim) were located to the north. The islands of Øygarden sat across the Hjeltefjorden to the west.

• List of former municipalities of Norway