Kalisz, city, Wielkopolskie województwo (province), west-central Poland, situated on the Prosna River.
The excavations of a prehistoric village and mention of the settlement as Calisia by the astronomer-geographer Ptolemy in the 2nd century ce are evidence of the town’s antiquity. A powerful castle stood there from the 12th to the 14th century. Kalisz obtained town rights in 1282.
Now industrialized, Kalisz specializes in textile production, a trade begun during the 15th century. Engineering and food processing are also important to the local economy. The city contains many scenic parks and historic churches, as well as a theatre and regional museum. Pop. (2011) 105,386.