Kirchen (Sieg) is a town and Luftkurort (climatic spa) in the district of Altenkirchen in the north of Rhineland-Palatinate, Germany. It is situated on the river Sieg, approx. 12 km southwest of Siegen. Among its notable features is the Freusburg castle.

Kirchen is the seat of the Verbandsgemeinde Kirchen (Sieg) (Verbandsgemeinde, collective municipality).

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. On the same day, the municipality was renamed Kirchen (Sieg). Kirchen (Sieg) was granted town rights on 6 November 2004.

• Jürgen Alzen (born 1962), automobile racing driver
• Uwe Alzen (born 1967), automobile racing driver
• Georg Bätzing (born 1961), Catholic clergyman, bishop of Limburg
• Christoph Klein (born 1964), pediatric oncologist and medical director of the Haunersch Children 's Hospital of the Clinic of the University of Munich
• Heinrich Kraemer (1842-1907), mayor, parliamentary and state parliament deputy
• Thomas Kraft (born 1988), football player
• Barbara Rudnik (1958-2009), actress
• Luca Stolz (born 1995), automobile racing driver

• Verbandsgemeinde Kirchen/Sieg