Meinerzhagen (German pronunciation: [ˈmaɪnɐtsˌhaːɡn̩] ^ⓘ; sometimes spelled Meinertzhagen) is a town in the Märkischer Kreis, North Rhine-Westphalia, Germany.

Meinerzhagen is located in the hills of the Sauerland. The highest elevation is the Nordhelle with 652 m above sea level, the lowest elevation at the Lister dam with 319m. 56% of the town area is covered by forests.

The town consists of the following villages and places:

In 1765 Meinerzhagen received city rights from King Frederick II of Prussia, however in 1865 the city abandoned them to save administrative costs. In 1846 the Amt Meinerzhagen was formed, covering both Meinerzhagen and the municipality of Valbert. On September 19, 1964, Meinerzhagen received city rights again.

In the communal reform of the district Altena in 1969, Meinerzhagen was merged with Valbert, the Amt Meinerzhagen was dissolved.

The family name of the British World War I officer Richard Meinertzhagen recalls an ancestor who came from this town.

The coat of arms of Meinerzhagen shows a red lion as the symbol of the Duchy of Berg, placed on a blue St. Andrew's cross on yellow ground, referring to the family von Badinghagen, which became extinct in the 17th century. The bottom part of the coat of arms shows the red-and-white-chequered bordure as the symbol of the Mark. A yellow horn is placed on top of the bordure, taken from the coat of arms of the municipality of Valbert. The coat of arms was granted on June 14, 1975.

Before the merging of Meinerzhagen and Valbert, the two towns as well as the Amt Meinerzhagen had their individual coats of arms. The coat of arms of Meinerzhagen dates back to at least 1857, as the town hall, built in 1857, already showed the coat of arms above its entrance. The coat of arms had a green bottom part, top left Saint Mary on a throne, holding a scepter, with Jesus as an infant, and top right a building with three towers and red roofs, and the sun and two stars above.