A geographical region that once contained manufacturing and other secondary industries (steel, shipbuilding, textiles etc) as primary employers which have long since shut down or moved out. Characterised by tumbleweeds, high unemployment and associated social problems (like substance abuse and crime), as these regions would typically have a blue collar workforce greater than what the hollowed-out commercial sector needs. Often there is a steady trickle of emigration out of rustbelts to places with more opportunity.

Rustbelts came about from the 1970s, as companies moved their manufacturing plants out of high cost, high regulation countries in the West, and later Japan. In the United States the rustbelt is said to consist of the north-west states of Illinois, Ohio, Michigan and Indiana, plus Pennsylvania. Detroit's population for example has shrunk from 1.8 million in 1950 to under a million in 2000. Other famous rustbelt regions include Yorkshire in Britain, Nowa Huta in Poland, Kansai in Japan, Germany's Ruhr, South Australia and north east China.

The re-establishment of new business such as service industries or specialised manufacturing might reverse the effect of economic degradation. The competitive advantage rustbelts have to offer business include established infrastructure (including plants and transportation links) and a ready supply of labour. Understanding the political capital that can be gained by reducing unemployment, often governments are instrumental in encouraging business set-ups in former rustbelt constituencies.