Finnøy is a former municipality in Rogaland county, Norway. The 104 square kilometres (40 sq mi) island municipality existed from 1838 until its dissolution in 2020 when it was merged into Stavanger Municipality. It was located in the traditional district of Ryfylke. The administrative centre of the municipality was the village of Judaberg.
 The municipality consisted of a number of islands on the south side of the Boknafjorden, about 24 kilometres (15 mi) northeast of the city of Stavanger. The Finnøy Tunnel connects the two islands of Finnøy and Talgje to the mainland. The rest of the islands are accessible only by boat.
 Finnøy is an agricultural community dominated by dairy, meat, poultry, and fish farming products, with strong horticultural traditions, mainly greenhouse production of tomatoes, as well as some tourism.
 Prior to its dissolution in 2020, the 104-square-kilometre (40 sq mi) municipality is the 375th largest by area out of the 422 municipalities in Norway.  Finnøy was the 256th most populous municipality in Norway with a population of 3,235.  The municipality's population density was 31.4 inhabitants per square kilometre (81/sq mi) and its population has increased by 21.1% over the last decade.
 The parish of Finnø was established as a municipality on 1 January 1838 (see formannskapsdistrikt law). It originally encompassed the islands of Finnøy, Talgje, and Fogn as well as the small surrounding islets and the southeasternmost corner of the island of Rennesøy. On 1 January 1918, the part of Finnøy located on the island of Rennesøy (population: 72) was transferred from Finnøy to the neighboring municipality of Rennesøy.
 During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1965, the municipality of Finnøy was enlarged when it was merged with the entire municipality of Sjernarøy (population: 819), the northeastern part of Ombo island (population: 89) from the municipality of Jelsa, and the Fisterøyene islands (population: 246) from the municipality of Fister.
 On 1 January 2020, the municipalities of Finnøy, Rennesøy, and Stavanger were merged into one, large municipality called Stavanger.
 The municipality (originally the parish) is named after the island of Finnøy (Old Norse: Finney) since the historic Hesby Church was built there. The meaning of the first element is uncertain. It is possibly from the word finna which is the local name for Nardus stricta. Another possibility is that it comes from the old male name finni. The last element is ey which means "island". Historically, the name of the municipality was spelled Finnø. On 3 November 1917, a royal resolution changed the spelling of the name of the municipality to Finnøy. The letter y was added to the end of the word to "Norwegianize" the name (ø is the Danish word for "island" and øy is the Norwegian word).
 The coat of arms was granted on 23 September 1983 and it was in use until 1 January 2020 when the municipality was dissolved. The official blazon is "Azure, a winged arrowhead argent in bend" (Norwegian: På blå grunn ei vengja sølv pil på skrå oppover). This means the arms have a blue field (background) and the charge is a winged arrowhead. The charge has a tincture of argent which means it is commonly colored white, but if it is made out of metal, then silver is used. The arms were derived from the arms of the Hestbø family (which included Ogmund Finnsson), one of the mightiest families in the area in the 14th century. They had their stronghold on their Hesby estate on the island of Finnøy in the municipality of Finnøy. The arms were designed by Harald Hallstensen. The municipal flag has the same design as the coat of arms. 
 The Church of Norway had three parishes (sokn) within the municipality of Finnøy. It was part of the Tungenes prosti (deanery) in the Diocese of Stavanger.
 Finnøy was at the top of its power in the middle of the fourteenth century when the King's representative Ogmund Finnsson had his seat at Hesby on the west side of the island of Finnøy. The medieval, stone Hesby Church, dating back to at least the thirteenth century, still stands at Hesby.
 It is often claimed that the Norwegian mathematician Niels Henrik Abel (1802–1829) was born on Finnøy, since his father Søren Georg acted as rector there. Recent studies indicates, however, that he was born in Nedstrand, a nearby parish. However, he was raised on Finnøy.
 The island municipality of Finnøy was located on the south side of the Boknafjorden. The main islands of Finnøy included Finnøy, Talgje, Fogn, Halsnøya, Sjernarøyane, and the north and west parts of the island of Ombo. The islands of Talgje and Finnøy are connected to the mainland by the undersea Finnøy Tunnel. The rest of the islands are only accessible by boats.
 While it existed, this municipality was responsible for primary education (through 10th grade), outpatient health services, senior citizen services, unemployment, social services, zoning, economic development, and municipal roads. 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 municipality was under the jurisdiction of the Ryfylke District Court and the Gulating Court of Appeal.
 The municipal council (Kommunestyre) of Finnøy was made up of 21 representatives that were elected to four year terms. The party breakdown for the councils was as follows:
 The mayors (Norwegian: ordfører) of Finnøy (incomplete list):