Geilenkirchen is a town in the district Heinsberg, in North Rhine-Westphalia, Germany. It is situated near the border with the Netherlands, on the river Wurm, approx. 15 km north-east of Heerlen and 20 km north of Aachen.
It was the site of Operation Clipper in November 1944.
The town gives its name to nearby NATO Air Base Geilenkirchen. The base is home to 17 E-3A airborne early warning and control aircraft manned by crews from 14 nations.
On July 24, 2019 the highest temperature ever recorded in Germany was measured in Geilenkirchen with 40.5 degrees Celsius during a heat wave that affected much of Europe. The record was broken the following day when temperature in Lingen reached 42.6 degrees Celsius.