Chimay is a city and municipality of Wallonia located in the province of Hainaut, Belgium. In 2006, Chimay had a population of 9,774. The ar…Chimay is a city and municipality of Wallonia located in the province of Hainaut, Belgium. In 2006, Chimay had a population of 9,774. The area is 197.10 km² which gives a population density of 50 inhabitants per km². It is the source of the Oise River.