The history of Schwelm goes back to the ninth century, where it is first mentioned as "Suelmiu". The city of Schwelm was officially established in 1496 and became seat of the Ennepe-Ruhrdistrict in 1929. According to its area, Schwelm is the smallest town in North Rhine-Westphalia.
Schwelm is home to the "Brauerei Schwelm", the Schwelm Brewery, one of the few remaining private breweries in Germany. It was started in 1830 by Haarmann & Kathagen, the brewery was one of the first worldwide to switch from wooden to metal barrels. The original office building of the brewery, the "Rietz'sche Haus" built in 1701, is still in use today.
The oldest piano manufacturer in the world is located in Schwelm. Since 1794, "Rud. Ibach Sohn" has been building pianos and, until 1904, organs in Schwelm.