(; ) is a Danish town in the

Region of Southern Denmark The Region of Southern Denmark (, ; , ; ) is an administrative region of Denmark established on Monday 1 January 2007 as part of the 2007 Danish Municipal Reform, which abolished the traditional counties ("amter") and set up five larger regions ...

. It is the main town and the administrative seat of Sønderborg Municipality (Kommune). The town has a population of 28,333 (1 January 2025),BY3: Population 1. January by urban areas, area and population density
The Mobile Statbank from

Statistics Denmark Statistics Denmark () is a Danish governmental organization under the Ministry of the Interior and Housing, reporting to the Minister of Economic and Internal Affairs. The organization is responsible for creating statistics on the Danish society ...

in a municipality of 74,096. In recent times, Sønderborg is a center for trade, tourism, industry, and education in the region of Southern Denmark. The town is the headquarters for several industrial companies. Sønderborg joined the UNESCO Global Network of Learning Cities in 2016.

Overview

The town of Sønderborg is home to Sønderborg Castle (''Sønderborg Slot''), the

Royal Danish Army The Royal Danish Army (; ; ) is the land-based branch of the Danish Armed Forces, together with the Danish Home Guard. For the last decade, the Royal Danish Army has undergone a massive transformation of structures, equipment and training methods ...

's Sergeant School (until 2013) and Sandbjerg Estate (''Sandbjerg Gods''). Sønderborg castle is in the centre of the town, and houses a museum focusing on the history and culture of the area. The museum is open all year. Sandbjerg Estate, which had belonged for many years to the Dukes of Sønderborg, and then to the Reventlow family, was donated to

Aarhus University Aarhus University (, abbreviated AU) is a public research university. Its main campus is located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra Group, the Guild, and Ut ...

in 1954. In addition, Sønderborg has a castle-like barracks built by the German military in 1906, placed centrally by Als Fjord, opposite Alsion (see picture below). The old part of Sønderborg is located on the island of

Als Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or—in the United States—Lou Gehrig's disease (LGD), is a rare, terminal neurodegenerative disorder that results in the progressive loss of both upper and low ...

, but some of its western

suburb A suburb (more broadly suburban area) is an area within a metropolitan area. They are oftentimes where most of a metropolitan areas jobs are located with some being predominantly residential. They can either be denser or less densely populated ...

s have spread onto the mainland of

Jutland Jutland (; , ''Jyske Halvø'' or ''Cimbriske Halvø''; , ''Kimbrische Halbinsel'' or ''Jütische Halbinsel'') is a peninsula of Northern Europe that forms the continental portion of Denmark and part of northern Germany (Schleswig-Holstein). It ...

into what had been the interior of the fort of

Dybbøl Dybbøl is a small town with a population of 2,357 (1 January 2024)Second Schleswig War The Second Schleswig War (; or German Danish War), also sometimes known as the Dano-Prussian War or Prusso-Danish War, was the second military conflict over the Schleswig–Holstein question of the nineteenth century. The war began on 1 Februar ...

of 1864, Sønderborg was situated in the

Duchy of Schleswig The Duchy of Schleswig (; ; ; ; ; ) was a duchy in Southern Jutland () covering the area between about 60 km (35 miles) north and 70 km (45 mi) south of the current border between Germany and Denmark. The territory has been div ...

, a Danish

fief A fief (; ) was a central element in medieval contracts based on feudal law. It consisted of a form of property holding or other rights granted by an overlord to a vassal, who held it in fealty or "in fee" in return for a form of feudal alle ...

, so its history is properly included in the contentious history of Schleswig-Holstein. In the 1920 Schleswig Plebiscite that returned

Northern Schleswig Northern may refer to the following: Geography * North, a point in direction * Northern Europe, the northern part or region of Europe * Northern Highland, a region of Wisconsin, United States * Northern Province, Sri Lanka * Northern Range, a ra ...

to Denmark, 43.8% of the city of Sønderborg's inhabitants voted for the cession to Denmark and 56.2% voted for remaining part of Germany.

Geography

The town of Sønderborg lies on both sides of Alssund; the narrow strait between these two sides is called Als Strait (''Alssund''). Two road bridges connect the city across the strait: the Als Strait Bridge (''Alssundbro''), built in 1978–1981; and the King

Christian X Christian X (; 26 September 1870 – 20 April 1947) was King of Denmark from 1912 until his death in 1947, and the only King of Iceland as Kristján X, holding the title as a result of the personal union between Denmark and independent Ice ...

's Bridge (''Kong Christian Xs Bro''), built in 1925–1930.

Education

Higher education

Sønderborg hosts several institutions of higher education. the

University of Southern Denmark The University of Southern Denmark (, SDU) has campuses located in Southern Denmark and on Zealand. It offers a number of joint programmes in co-operation with the University of Flensburg and the University of Kiel. Contacts with regional indu ...

University College South University College South Denmark Internationalt > English">University College Syd > Forside > Internationalt > English/ref> () is a university college in the southern part of Denmark. It offers bachelor courses in various disciplines and has appr ...

(), an
Business Academy SouthWest
Due to the local economy, the University of Southern Denmark offers several types of degrees in engineering such as: mechatronics; electronics; innovation and business; as well as degrees in economics, languages and European studies.

Secondary education

The technical school EUC Syd has a campus in Sønderborg, and offers a variety of trades programs, as well as the HTX high school diploma and the

International Baccalaureate The International Baccalaureate Organization (IBO), more commonly known as the International Baccalaureate (IB), is a nonprofit foundation headquartered in Geneva, Switzerland, and founded in 1968. It offers four educational programmes: the I ...

Diploma program.

Economy

Sønderborg is an economic hub in the region of Southern Denmark, with industries within

electronics Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other Electric charge, electrically charged particles. It is a subfield ...

manufacturing Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of the secondary sector of the economy. The term may refer ...

food processing Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing takes many forms, from grinding grain into raw flour, home cooking, and complex industrial methods used in the mak ...

Information Technology Information technology (IT) is a set of related fields within information and communications technology (ICT), that encompass computer systems, software, programming languages, data processing, data and information processing, and storage. Inf ...

and

telecommunications Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...

among others, with several companies headquartered in and around the town. The

high-tech High technology (high tech or high-tech), also known as advanced technology (advanced tech) or exotechnology, is technology that is at the cutting edge: the highest form of technology available. It can be defined as either the most complex or ...

industry includes the manufacturing and development of electronics, machines, industrial equipment, and software. Companies of major importance in the

sector headquartered in the region include

Danfoss Danfoss is a Danish multinational company, based in Denmark, with more than 41,928 employees globally. Danfoss was founded in 1933 by engineer Mads Clausen. History Beginning (1933–1966) In 1933 Mads Clausen (1905–1966) founded ''D ...

who employs around 1000 people in Sønderborg, and 40,000 people globally. Linak, headquartered in Nordborg 25 km from Sønderborg, produces linear

actuators An actuator is a component of a machine that produces force, torque, or displacement, when an electrical, pneumatic or hydraulic input is supplied to it in a system (called an actuating system). The effect is usually produced in a controlled way. ...

for a variety of different applications, from agriculture to healthcare, and employs around 1,100 people in the region. Maersk container industries(MCI), a part of the

Maersk (), usually known simply as Maersk ( ), is a Danish Freight transport, shipping and logistics company founded in 1904 by Arnold Peter Møller and his father Peter Mærsk Møller. Maersk's business activities include Port operator, port operat ...

group, manufactures refrigerated and refrigeration machines shipping containers, has its headquarters in Sønderborg. The

and meat packing group, Danish Crown has a slaughterhouse located in the town of Blans, outside of Sønderborg. The slaughterhouse produces pork and meat products for consumption, and employs around 940 people. BHJ is a leading supplier of animal proteins for the international food and pet food industries, with headquarters in

Gråsten Gråsten (; ) is a town with a population of 4,298 (1 January 2025) on the east coast of the Jutland peninsula in south Denmark by the Nybøl Nor at an inlet of the Flensburg Fjord. It belongs to the Sønderborg municipality in Region of Souther ...

, outside of Sønderborg and more than 900 employees worldwide. In

, TDC A/S operates a callcenter employing roughly 370 employees. In August 2014, TDC planned to outsource around 700 full-time positions to American company Sitel, by 2015. Skyways technics, an aircraft service and repair company is headquartered at Sønderborg Airport and has 150 employees in Sønderborg and Billund.

Saab AB Saab AB (originally , , acronym SAAB), with subsidiaries collectively known as the Saab Group (), is a Swedish aerospace and defense company, defence company primarily operating from Sweden. The company is headquartered in Stockholm, but its de ...

also has offices in the town, mainly focused on sales and engineering.

Transportation

Rail

Sønderborg is served by Sønderborg railway station, which opened in 1901, and is located next to Alsion. It is the eastern terminus of the Sønderborg railway line which connects Sønderborg with and the rest of the Danish rail network. Sønderborg station offers frequent direct services to

Fredericia Fredericia () is a town located in Fredericia Municipality in the southeastern part of the Jutland peninsula in Denmark. The city is part of the Triangle Region Denmark, Triangle Region, which includes the neighbouring cities of Kolding and Vej ...

and

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

, as well as a direct

InterCity InterCity (commonly abbreviated ''IC'' on timetables and tickets) is the train categories in Europe, classification applied to certain long-distance passenger train services in Europe. Such trains (in contrast to InterRegio, regional train, r ...

service to

Copenhagen Airport Copenhagen Airport, Kastrup (, ) is an international airport serving Copenhagen, the capital of Denmark, as well as the wider Øresund Region, including Zealand and the southern Sweden, Swedish province of Scania. In 2023 it was the largest ai ...

Air

The city is served by Sønderborg Airport. The airline, Alsie Express provides flights directly to

and seasonal flights to destinations such as

Bornholm Bornholm () is a List of islands of Denmark, Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland. Strategically located, Bornholm has been fought over for centuries. I ...

and

Naples Naples ( ; ; ) is the Regions of Italy, regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 908,082 within the city's administrative limits as of 2025, while its Metropolitan City of N ...

Ferry

Molslinjen operates daily ferry services from Fynshav to Bøjden on the island of

Funen Funen (, ), is the third-largest List of islands of Denmark, island of Denmark, after Zealand and North Jutlandic Island, Vendsyssel-Thy, with an area of . It is the List of islands by area, 165th-largest island in the world. It is located in th ...

, with roads connecting the town to

Odense Odense ( , , ) is the third largest city in Denmark (after Copenhagen and Aarhus) and the largest city on the island of Funen. As of 1 January 2025, the city proper had a population of 185,480 while Odense Municipality had a population of 210, ...

and further to

Zealand Zealand ( ) is the largest and most populous islands of Denmark, island in Denmark proper (thus excluding Greenland and Disko Island, which are larger in size) at 7,031 km2 (2715 sq. mi.). Zealand had a population of 2,319,705 on 1 Januar ...

and

Notable natives

The Arts

Christian August Lorentzen Christian August Lorentzen (10 August 1749 – 8 May 1828) was a Danish painter. Early life and education Christian August Lorentzen was born in Sønderborg, Denmark. He was the son of Hans Peter Lorentzen and Maria Christina Hansdatter. His ...

(1749 in Sønderborg – 1828) a Danish painter and instructor of Martinus Rørbye * Herman Bang (1857 in Asserballe – 1912) an author, of the Modern Breakthrough * Kamma Svensson (1908 in Sønderborg – 1998) a Danish illustrator, contributed to ''

Politiken ''Politiken'' is a leading Danish daily broadsheet newspaper, published by JP/Politikens Hus in Copenhagen, Denmark. It was founded in 1884 and played a role in the formation of the Danish Social Liberal Party. Since 1970 it has been indepe ...

'' * K.R.H. Sonderborg (1923 in Sønderborg – 2008) a

new media art New media art includes artworks designed and produced by means of new media, electronic media technologies. It comprises virtual art, computer graphics, computer animation, digital art, interactive art, sound art, Internet art, video games, robo ...

ist and musician. * Johannes Carstensen (1924 in Sønderborg – 2010) a neo-impressionistic Odsherred painter * Per Nielsen (born 1954 in Sønderborg) a popular Danish trumpet player * Søren Solkær (born 1969 in Sønderborg) a Danish photographer * Sune Rose Wagner (born 1973 in Sønderborg) a songwriter, guitarist and vocalist, playing in the rock group The Raveonettes

Public thinking and public service

* Baron Otto Grote zu Schauen (1636/1637 in Sønderborg – 1693) an Hanoverian statesman * Lars Frodesen (1889 in Sønderborg – 1921) a writer and philosopher, heavily inspired by

Blaise Pascal Blaise Pascal (19June 162319August 1662) was a French mathematician, physicist, inventor, philosopher, and Catholic Church, Catholic writer. Pascal was a child prodigy who was educated by his father, a tax collector in Rouen. His earliest ...

* Frode Kristoffersen (1931–2016), journalist and politician * Else Roesdahl (born 1942 in Sønderborg) a historian, educator and archaeologist * Vibeke Vasbo (born 1944 in Tandslet) a writer and women's rights activist * Ralf Pittelkow (born 1948 in Sønderborg) a commentator on both radio and TV * Tom Buk-Swienty (born 1966) a historian, journalist and author, raised in Sønderborg * Lisbeth Bech Poulsen, (Danish Wiki) (born 1982 n Sønderborg) politician,Members of the Danish Parliament
retrieved 26 March 2018 member of the Danish

folketing The Folketing ( , ), also known as the Parliament of Denmark or the Danish Parliament in English, is the unicameral national legislature (parliament) of the Kingdom of Denmark — Denmark proper together with the Faroe Islands and Greenland. E ...

for

Socialistisk Folkeparti The Green Left, since March 2022 the English name for Socialistisk Folkeparti (, , abbr. SF), is a democratic socialist political party in Denmark. SF was founded on 15 February 1959 by Aksel Larsen, a former leader of the Communist Party of ...

Science and business

* Westye Egeberg (1770 in Sønderborg – 1830) a Danish-Norwegian timber and lumber businessman * Jakob Nielsen (1890 in Mjels – 1959) a mathematician, worked on

automorphism In mathematics, an automorphism is an isomorphism from a mathematical object to itself. It is, in some sense, a symmetry of the object, and a way of mapping the object to itself while preserving all of its structure. The set of all automorphism ...

s of surfaces * Johannes Iversen (1904 in Sønderborg – 1972) a Danish palaeoecologist * Peder Moos (1906 in Sønderborg – 1991) a Danish furniture designer and cabinetmaker *

Jørgen Mads Clausen Jørgen Mads Clausen (born 23 September 1948) is a Danish businessman and philanthropist. He was the CEO of Danfoss, the Danish heating, refrigeration, and air conditioning company, from 1996 to 2009 then chairman until 2022. The company was foun ...

(born 1948 in Elsmark) Chairman of the board of

* Lothar Göttsche (born 1961 in Sønderborg) a German mathematician, works on

algebraic geometry Algebraic geometry is a branch of mathematics which uses abstract algebraic techniques, mainly from commutative algebra, to solve geometry, geometrical problems. Classically, it studies zero of a function, zeros of multivariate polynomials; th ...

* Niels Christiansen (born 1966 in Sønderborg) a Danish businessman, CEO of

Lego Lego (, ; ; stylised as LEGO) is a line of plastic construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. Lego consists of variously coloured interlocking plastic bricks made of acrylonitri ...

* Jens Martin Skibsted (born 1970 in Sønderborg) a Danish designer, entrepreneur and author * Thorsten Mauritsen (born 1977 in Sønderborg) a Danish climate scientist

Sport

* Ludvig Drescher (1881 in Sønderborg – 1917) an amateur football goalkeeper, team silver medallist at the

1908 Summer Olympics The 1908 Summer Olympics (officially the Games of the IV Olympiad and also known as London 1908) were an international multi-sport event held in London, England, from 27 April to 31 October 1908. The 1908 Games were originally schedu ...

* Verner Blaudzun (born 1946 in Sønderborg) a former cyclist, team bronze medalist at the

1976 Summer Olympics The 1976 Summer Olympics (), officially known as the Games of the XXI Olympiad () and officially branded as Montreal 1976 (), were an international multi-sport event held from July 17 to August 1, 1976, in Montreal, Quebec, Canada. Montreal ...

* Palle Jensen (born 1953 in Sønderborg) former handball player, competed in the

1976 Events January * January 2 – The International Covenant on Economic, Social and Cultural Rights enters into force. * January 5 – The Pol Pot regime proclaims a new constitution for Democratic Kampuchea. * January 18 – Full diplomatic ...

and

1980 Summer Olympics The 1980 Summer Olympics (), officially known as the Games of the XXII Olympiad () and officially branded as Moscow 1980 (), were an international multi-sport event held from 19 July to 3 August 1980 in Moscow, Soviet Union, in present-day Russ ...

* Michael Søgaard (born 1969 in Sønderborg) a Danish badminton player * Anders Hansen (born 1970 in Sønderborg) a semi-retired Danish professional golfer. * Lars Christiansen (born 1972 in Sønderborg) a former team handball player, played 338 games for the Denmark men's national handball team * Simon Poulsen (born 1984 in Sønderborg) a footballer, 31 caps with the

Denmark national football team The Denmark national football team ( or ''herrelandsholdet'') represents Denmark and Greenland in men's international Association football, football competitions. It is controlled by the Danish Football Association (DBU), the governing body for ...

* Nicki Thiim (born 1989 in Sønderborg) a professional Danish race-car driver * Sara Keçeci (born 1994 in Sønderborg) a Turkish-Danish female handball goalkeeper * Daniel Bachmann Andersen (born in 1990 in Sønderborg) a Danish equestrian athlete

Other

The formerly ruling family of

Schleswig-Holstein-Sonderburg Schleswig-Holstein-Sonderburg was the name of a branch line of the House of Oldenburg as well as the name of their land. It existed from 1564 until 1668 and was a titular duchy under the King of Denmark, rather than a true territorial dukedom in ...

married into Kings and Queens

Panoramic view

Culture

Musical institutions

Sønderborg is home to the South Jutland Symphony Orchestra Sønderjyllands Symfoniorkester.

Attractions

Sønderborg Castle is today a museum about the history of Southern Denmark. The science park Universe (earlier known as Danfoss univers) is located just north of Sønderborg.

In literature

In Chapter 4 of Erskine Childers’ 1903 novel '' The Riddle of the Sands'', the protagonists, two English yachtsmen, visit Sonderburg, then under German rule: "Fascinating Sonderburg, with its broad-eaved houses of carved woodwork, each fresh with cleansing, yet reverend with age; its fair-haired Viking-like men and rosy, plain-faced women, with their bullet foreheads and large mouths; Sonderburg still Danish to the core under its Teuton veneer. Crossing the bridge I climbed the Dybbol – dotted with memorials of that heroic defence – and thence could see the wee form and gossamer rigging of our yacht on the silver ribbon of the Sound. (...) In the old quarter I bargained over eggs and bread with a dear old lady, pink as a debutante, who made a patriotic pretence of not understanding German."

References

External links

* * {{DEFAULTSORT:Sonderborg Municipal seats of the Region of Southern Denmark Municipal seats of Denmark Cities and towns in the Region of Southern Denmark Port cities and towns of the Baltic Sea Sønderborg Municipality