Iserlohn (German: [iːzɐˈloːn] ; Westphalian: Iserlaun) is a city in the Märkischer Kreis district, in North Rhine-Westphalia, Germany. It is the largest city by population and area within the district and the Sauerland region.

Iserlohn is located at the north end of the Sauerland near the Ruhr river, in West-Central Germany.

The Pancratius church (also called Bauernkirche) is believed to have been founded in around 985, but the first written document mentioning lon dates only from 1150. In 1237 the Count of the Mark gave Iserlohn municipal rights. In 1975 the city, which had been an urban district before, incorporated the surrounding ex-municipalities of Letmathe, Hennen, Sümmern and Kesbern, and became part of the district "Märkischer Kreis". As a larger mid-sized city, Iserlohn, however, still has a special status compared to most other municipalities in the district. This means that the city takes on tasks more usually performed by the district, such as social and youth affairs, hence it is comparable to an urban district.

The current mayor of Iserlohn is Michael Joithe, a member of the voter group Die Iserlohner. The most recent mayoral election was held on 13 September 2020, with a runoff held on 27 September, and the results were as follows:

Candidate		Party	First round		Second round
			Votes	%	Votes	%
	Eva-Barbara Kirchhoff	Christian Democratic Union	13,275	39.8	11,912	49.8
	Michael Joithe	Die Iserlohner	5,273	15.8	12,007	50.2
	Martin Luckert	Social Democratic Party	5,015	15.0
	Manuel Huff	The Left	2,864	8.6
	Martin Isbruch	Alliance 90/The Greens	2,692	8.1
	Daniel Bläsing	Alternative for Germany	1,608	4.8
	Claudio Vurro	Independent	1,521	4.6
	Hans Herbers	Independent Voters' Association	592	1.8
	Martin Radojcic	Independent	233	0.7
	Robert Gustävel	Independent	194	0.6
	Michael Klammt	Independent	129	0.4
Valid votes			33,396	99.2	23,919	98.3
Invalid votes			279	0.8	419	1.7
Total			33,675	100.0	24,338	100.0
Electorate/voter turnout			72,958	46.2	72,849	33.4
Source: City of Iserlohn (1st round, 2nd round)

The Iserlohn city council governs the city alongside the Mayor. The most recent city council election was held on 13 September 2020, and the results were as follows:

Party		Votes	%	+/-	Seats	+/-
	Christian Democratic Union (CDU)	11,817	35.6	3.6	24	4
	Social Democratic Party (SPD)	6,337	19.1	13.3	13	3
	Die Iserlohner	4,397	13.2	New	9	New
	Alliance 90/The Greens (Grüne)	3,713	11.2	4.3	8	5
	The Left (Die Linke)	2,498	7.5	0.5	5	1
	Alternative for Germany (AfD)	1,985	6.0	0.2	4	1
	Free Democratic Party (FDP)	1,483	4.5	0.4	3	1
	Independent Voters' Association (UWG)	960	2.9	0.7	2	1
	Independent Radojcic	43	0.1	New	0	New
Valid votes		33,233	98.8
Invalid votes		420	1.2
Total		33,653	100.0		68	18
Electorate/voter turnout		72,958	46.1
Source: City of Iserlohn

The Dechenhöhle caves were discovered in 1868 during the construction of the railway line Hagen-Iserlohn. 360 metres are accessible for visitors, and there are many stalactites and stalagmites in the cave.

The Danzturm, located on the southern hill overlooking the old city, is a landmark and featured on the logo of the local brewery (Iserlohner). The tower has views of the valley and surrounding hills and is open to the public with a small inn at the base.

In the 18th century, the town became known for its Iserlohn boxes, a form of tobacco or snuff box with an engraved or embossed lid that often featured an image of former Prussian King Frederick the Great.

The city is home of the Iserlohn Roosters, a DEL (first-division) ice hockey team. The Roosters joined the DEL in 2000 and developed from a low-budget team to a solid one that regularly competes for a Playoff-spot. The club plays its home games at the Eissporthalle Iserlohn, which holds 4,967 spectators. The original club, EC Deilinghofen, was founded in 1959 and went bankrupt in 1987. The second club, ECD Sauerland, existed from 1988 to 1994. In 1994, Iserlohner EC was founded.

Iserlohn has 15 elementary schools and 12 secondary schools (3 Gymnasien, 1 Gesamtschule, 3 Realschulen, 5 Hauptschulen).

Two universities of applied sciences are also located in the city. The headquarters, together with a major branch, of the South Westphalia University of Applied Sciences (also: Fachhochschule Südwestfalen (FH SWF)) offering engineering and informatics programmes is located in the city centre on Alexanderhöhe. The Gesamtschule Seilersee (BiTS) is a private, state-approved business school with a campus near the Seilersee.

The Schützenfest is a famous festival which takes place every year, and is central to Iserlohner's cultural life - and the town's identity. It is held at the Parkhalle, Alexanderhöhe.

At the same time as the Shooters festival (Schützenfest) the Iserlohn Peace committee (FriedensPlenum) has held a 3 day free benefit music festival around the farmers church (Bauernkirche) since 1991.

Iserlohn's coat of arms features, in the middle, Saint Pancras (St. Pancratius), who is patron of the oldest church in Iserlohn. He is depicted between two towers of the historic city wall. The checked fess below the saint is derived from the arms of the Counts of the Mark.

Iserlohn is twinned with:

• Johann Stephan Pütter (1725–1807), Reichspublizist and teacher of state law
• Friedrich Soennecken (1848–1919), businessman, entrepreneur, inventor and graphic artist
• Alexander Pfänder (1870–1941), philosopher
• Karl Rasche (1892–1951), SS honor and rank leader for special use with the rank of Obersturmbannführer and board member and spokesman of the Dresdner Bank
• Wilhelm Wessel (1904–1971), painter
• Curt Rechel (1902–1973), Navy officer
• Walter Bosse (1904-1979), artist, designer, and potter
• Richard Friederich Arens (1919–2000), mathematician
• Gerd Roellecke (1927–2011), jurist and legal philosopher
• Aloys Kontarsky (1931–2017), pianist
• Alfons Kontarsky (1932–2010), pianist
• Bernhard Kontarsky (born 1937), conductor and pianist
• Jochen Busse (born 1941), actor and cabaret artist
• Helmut Neuhaus (born 1944), historian on Early modern period
• [2]Albert Ernst (1912-1986) World War 2 tank ace, who saved the city by peacefully surrendering to US troops
• Harm Klueting (born 1949), Roman Catholic clergyman, historian, theologian and university lecturer
• Volker Fischer (born 1950), fencer
• Ulrich Walter (born 1954), astronaut
• Gordon Brown (1958–2020), sculptor
• Timothy Paul Evans (born 1962), British general lieutenant and commander of the ARRC
• Matthias Mellinghaus (born 1965), rowing sportsman, film director and assistant director, Olympiasieger 1988
• Brian Glynn (born 1967), ice hockey player
• Marsha Wattanapanich (born 1970), Thai singer and actress
• Markus Giesler (born 1976), consumer researcher
• Caput [de] (born Soner Duman) (born 1983), rapper
• Thore Schölermann (born 1984), actor
• Dieter Orendorz (born 1992), ice hockey player
• David Beckmann (born 2000), car racing driver
• Monty Don (born 1955), gardener

• Götz Bettge: Iserlohn-Lexikon. Iserlohn 1987. ISBN 3-922885-37-3.
• Ernst Dossmann: Iserlohner Tabaksdosen erzählen. Ein Einblick in die wirtschaftlichen, gesellschaftlichen, politischen und militärischen Verhältnisse und das Aufblühen von Gewerbe, Industrie und Handel im märkisch-westfälischen Wirtschaftsraum während der Regierungszeit Friedrichs des Großen, dargestellt an bekannten Iserlohner Industrieerzeugnissen. 1981. ISBN 3-922885-01-2.
• Margret Kirchhoff: Pulsschläge einer Stadt. Die Oberste Stadtkirche Iserlohn – Zeitbilder und Momentaufnahmen. 2003. Eigenverlag Dr. Margret Kirchhoff.
• Fritz Kühn: Liebes altes Iserlohn. (released about 1956). Westfalenverlag Dortmund
• Peter Müller und Günter Stalp: Unsere gute alte Straßenbahn. Eine Reise in die Vergangenheit. Iserlohn 1995. ISBN 3-922885-78-0.
• Hans-Herbert Mönnig Verlag Iserlohn (no author mentioned): Iserlohn – unsere lebendige Stadt. Ein Bildband von Iserlohnern für Iserlohner. Iserlohn 1997. ISBN 3-922885-93-4.
• Heinz Stoob (†): Westfälischer Städteatlas; Band: I; 9 Teilband (Stadtmappe Iserlohn). Im Auftrage der Historischen Kommission für Westfalen und mit Unterstützung des Landschaftsverbandes Westfalen-Lippe; edited by Heinz Stoob and Wilfried Ehbrecht. Dortmund-Altenbeken, 1975. ISBN 3-89115-336-8.

• Official website (in German)
• Newspaper Iserlohner Kreisanzeiger und Zeitung (in German)