Blankenheim is a municipality in the district of Euskirchen in the state of North Rhine-Westphalia, Germany.

Blankenheim is located in the Eifel hills, approximately 27 km (17 mi) south-west of Euskirchen.

The river Ahr has its source in the centre of Blankenheim, in the cellar of a half timbered house.

In the year 721, Blankenheim is mentioned for the first time as "Blancio" in a document.

Today, the municipality is called in Eifel dialect as "Blangem" and has got a long carnival tradition.