Tysnes (Urban East Norwegian: [ˈtŷːsneːs]) is a municipality in Vestland county, Norway. It is located in the traditional district of Sunnhordland. The administrative centre is the village of Uggdal. Other population centres in Tysnes include the villages of Våge and Onarheim. The island municipality is located in a group of islands near the mouth of the Hardangerfjorden. The majority of the municipal population lives on the island of Tysnesøya, the largest island in the municipality.

The 255-square-kilometre (98 sq mi) municipality is the 283rd largest by area out of the 356 municipalities in Norway. Tysnes is the 232nd most populous municipality in Norway with a population of 2,910. The municipality's population density is 11.9 inhabitants per square kilometre (31/sq mi) and its population has increased by 6.4% over the previous 10-year period.

The historic parish of Tysnæs was established as a municipality on 1 January 1838 (see formannskapsdistrikt law). On 1 January 1907, the small portion of Tysnes located on the mainland (population: 67) was transferred to the neighboring municipality of Kvinnherad. The municipal borders have not changed since that time.

The municipality (originally the parish) is named after the old Tysnes farm (Old Norse: Týsnes) since the first Tysnes Church was built there. The first element is the genitive case of the name of the Old Norse god Týr. The last element is nes which means "headland".

This is probably the only place in Norway named after the god Týr. Several place names around the farm also have sacred meanings: Ve (holy place), Helgastein (holy rock), Godøy (the god's island), and Vevatnet (the holy lake). The old name of the big island of Tysnesøy was Njarðarlǫg (the district of the god Njord). Recently, a sun phenomenon connected to the original Tysnes headland has been discovered, and this seems to be the starting-point of the sacral name complex.

The first coat of arms for Tysnes was adopted on 28 October 1971 and it was in use until 1 January 2020 when a new coat of arms replaced it. The official blazon is "Azure, under a chevron two crossed axes argent" (Norwegian: På blå grunn to sølvfarga kryssede økser med sparre over). This means the arms have a blue field (background) and the charge is two crossed axes under a chevron. 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 seal of the medieval Onarheim guild (Olavsgildet). Onarheim is a village on the island of Tysnesøya which was historically a Viking Age center of power in the Sunnhordland region. The chevron above the axes was added to the municipal arms to distinguish it from the medieval arms and the arms for the old Hordaland county. The arms were designed by Magnus Hardeland. The municipal flag had the same design as the coat of arms.

The old coat of arms was never formally adopted because it was too similar to the coat of arms for Hordaland county and the government refused to approve it. After Hordaland county became part of the new Vestland county, the Hordaland arms were no longer used. Additionally, a law was also changed, giving the municipal councils the ultimate authority to determine their own coats of arms, so Tysnes decided to review their arms. The council debated approving the old arms or choosing to adopt the arms of the old Hordaland county (with different colors). In 2020, the council adopted a new coat of arms based on the old Hordaland arms. The official blazon is "Azure, under a royal crown two crossed axes argent" (Norwegian: På blå grunn to sølvfarga kryssede økser med krone over.). This means the arms have a blue field (background) and the charge is a two crossed axes under a three pointed crown. 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. This design was chosen because it more closely resembled the old Onarheim arms than the previous design. The municipal flag has the same design as the coat of arms.

The Church of Norway has three parishes (sokn) within the municipality of Tysnes. It is part of the Sunnhordland prosti (deanery) in the Diocese of Bjørgvin.

Churches in Tysnes

Parish (sokn)	Church name	Location of the church	Year built
Onarheim	Onarheim Church	Onarheim	1893
Reksteren og Uggdal	Reksteren Church	Reksteren	1937
	Uggdal Church	Uggdal	1876
Tysnes	Tysnes Church	Våge	1868

Tysnes Municipality is responsible for primary education (through 10th grade), outpatient health services, senior citizen services, welfare and other social services, zoning, economic development, and municipal roads and utilities. The municipality is governed by a municipal council of directly elected representatives. The mayor is indirectly elected by a vote of the municipal council. The municipality is under the jurisdiction of the Haugaland og Sunnhordland District Court and the Gulating Court of Appeal.

The municipal council (Kommunestyre) of Tysnes is made up of 21 representatives that are elected to four year terms. The tables below show the current and historical composition of the council by political party.

The mayors (Nynorsk: ordførar) of Tysnes:

The municipality consists of a group of islands, located south of the city of Bergen where the Hardangerfjorden and the coastal archipelago meet. The Bjørnafjorden lies north of the municipality and the Langenuen strait runs along the western side of the municipality. The largest of these islands, named Tysnesøya, can be reached from the mainland either by ferry to the village of Våge on the north side of the island or by the road bridge constructed on the eastern side of the island. The second largest island is Reksteren, which is connected to Tysnesøya by a small road bridge.

Historical population

Year Pop. ±% p.a. 1845 3,758 —     1855 4,110 +0.90% 1865 4,274 +0.39% 1875 4,464 +0.44% 1891 4,590 +0.17% 1900 4,603 +0.03% 1910 4,951 +0.73%	Year Pop. ±% p.a. 1920 4,416 −1.14% 1930 4,379 −0.08% 1946 4,009 −0.55% 1951 3,866 −0.72% 1960 3,559 −0.92% 1970 3,019 −1.63% 1980 2,774 −0.84%	Year Pop. ±% p.a. 1990 2,915 +0.50% 2000 2,843 −0.25% 2010 2,779 −0.23% 2020 2,869 +0.32% 2023 2,910 +0.47%
Source: Statistics Norway and Norwegian Historical Data Centre

• Anders Mowatt of Hugoland (ca. 1530 – ca. 1610 in Tysnes), a Scottish merchant, navy admiral, and landowner
• Axel Mowat (1592 in Tysnes – 1661), a Norwegian naval officer and land owner becoming Barony Rosendal
• Karen Mowat (ca. 1630 in Tysnes – 1675), a Norwegian noblewoman, heiress, and landowner of Scottish origins
• Claus Pavels Riis (1826–1886), a Norwegian author who settled in Tysnes as a landowner and gardener
• Olav Gurvin (1893 in Tysnes – 1974), a Norwegian musicologist and academic
• Johannes Heggland (1919 in Tysnes – 2008), a novelist, short story and children's literature writer, playwright, and politician
• Magnus Aarbakke (born 1934 in Tysnes), a Norwegian judge and Supreme Court Justice from 1994 to 2002

The newspaper Tysnes has been published in Tysnes since 1953.

• 
  Island of Tysnes
• 
  Midsummer festival, Island of Tysnes
• 
  National dress on the island of Tysnes
• 
  Ferry in Tysnes

• Municipal fact sheet from Statistics Norway (in Norwegian)
• Tysnes municipality home page
• Tysnes newspaper (in Norwegian)
• Tysnesingen online newspaper (in Norwegian)
• Video about the sun phenomenon connected to the Tysnes headland, pre-Christian cult and the sacral place names in the area