Finspång is a traditional industrial town. The first industries were established in 1580 when a Royal factory for cannon and cannon balls was chartered. The industry was to continue for 300 years under supervision of the Walloon/Dutch family De Geer. Finspång Castle was built by Louis Gerhard De Geer (1622-1695), and around it industries and an orangery developed into the town of Finspång. Today the two main industrial areas are those of turbines and metal processing.
Administratively Finspång remained part of the rural municipality Risinge until 1942, when it was made a market town (köping). Since 1971 it is the seat of the enlarged Finspång Municipality.