Lennestadt lies at the common point of the Ebbegebirge (in the west), Homert and Rothaargebirge (in the east) Nature Parks and is crossed by the river Lenne, a tributary to the Ruhr.

Lennestadt borders in the north on the communities of Eslohe and Finnentrop, in the east on Schmallenberg and Bad Berleburg, in the south on Kirchhundem, and in the west on the towns of Attendorn and Olpe.

Within Lennestadt's municipal area lie the following centres: Altenhundem, Altenvalbert, Bilstein, Bonzel, Bonzelerhammer, Brenschede, Bruchhausen, Burbecke, Elspe, Elsperhusen, Einsiedelei, Germaniahütte, Gleierbrück, Grevenbrück, Habbecke, Hachen, Haus Hilmecke, Haus Valbert, Halberbracht, Hengstebeck, Hespecke, Kickenbach, Kirchveischede, Kracht, Langenei, Maumke, Meggen, Melbecke, Milchenbach, Oberelspe, Obermelbecke, Obervalbert, Oedingen, Oedingermühle, Oedingerberg (formerly Berge), Saalhausen, Sporke, Stöppel, Theten and Trockenbrück.

The earliest traces of settlers in the current municipal area date to the Early Middle Ages.

The centres of Elspe and Oedingen were first mentioned in a document in 1000 that Emperor Otto III had issued.

The wavy bend stands for the river Lenne, the town's namesake, and the rose comes from the outlying centre of Oedingen.

Since 2001, the town has been awarding the Thomas-Morus-Preis to citizens “who in their acts have let themselves be led by the convictions of their conscience and who without regard to possible personal disadvantages through bravery and moral courage have thereby become examples to the good of others and our society.”[3] Lennestadt is twinned with:[4] The Kulturgemeinde Hundem-Lenne, founded in 1946, offers a cultural programme in the Pädagogisches Zentrum (PZ, “Educational Centre”), a venue with 480 seats at the Anne-Frank-Hauptschule in Meggen.

Among the town's regular events is the traditional Schützenfest (“fair featuring shooting matches”) that is held in all of the bigger centres each year.

Most prevalent are companies in the metal-working, machine building, automotive parts supply, and electrical industry.

Lennestadt is connected to the North Rhine-Westphalia Cycle Transport Network (Radverkehrsnetz NRW) and furthermore lies on the Lenneroute running from the Lenne's source on the Kahler Asten down to its mouth at the Hohensyburg (castle).