Kirchen (Sieg) is a town and Luftkurort (climatic spa) in the district of Altenkirchen in the north of Rhineland-Palatinate, Germany.

In early 1942, Kirchen and Wehbach were forcibly united with the Nazi government and renamed Kirchen-Wehbach (Sieg).

Despite protests from the people of Wehbach, this merger and renaming persisted even after the end of the war for two and a half decades, until additional former municipalities were annexed.

On 7 June 1969, the municipalities of Freusburg, Herkersdorf, Offhausen, Wingendorf, and Katzenbach, with the exception of the Unterbüdenholz district, which was incorporated into Brachbach, were amalgamated.

Kirchen (Sieg) was granted town rights on 6 November 2004.