Gilly is a town of Wallonia and a district of the municipality of Charleroi, located in the province of Hainaut, Belgium. It was a municipality of its own before the fusion of the Belgian municipalities in 1977. It houses the base of Fédération des Patros, a youth organisation. During the 1980s and 1990s it was also the home of an international group of Christian missionaries working with Operation Mobilisation.