Køge was founded by royal order at the first place south of Copenhagen that had a natural harbour. The order was issued in the years prior to 1288 when a town plan was designed. This plan is still valid for the old town centre. Køge was granted a municipal charter in 1288.
Køge is among the towns in Denmark that have the largest number of well preserved half timbered houses from the Renaissance period in its centre, including Denmark's oldest half timbered house from 1527, verified by a date inscription, and the oldest town hall still in use, dating from 1552.