Degerfors Municipality (Degerfors kommun) is a municipality in Örebro County in central Sweden. Its seat is located in the town of Degerfors.The northern part of the municipality was before 1925 part of Karlskoga Municipality, from which it was detached to form a new entity. It became a market town (köping) in 1943. In 1967 it was amalgamated with a part of the dissolved Svartå Municipality.