Kietlin [ˈkʲɛtlin] is a village in the administrative district of Gmina Radomsko, within Radomsko County, Łódź Voivodeship, in south-central Poland. It lies approximately 5 kilometres (3 mi) north-east of Radomsko and 78 km (48 mi) south of the regional capital Łódź.

Following the joint German-Soviet invasion of Poland, which started World War II in September 1939, the village was occupied by Germany. In October 1943, the German gendarmerie committed a massacre of 11 people in Kietlin. The victims were three Poles (two men and one woman) and eight Jews (including children), whom they sheltered from the Holocaust.