Gilly is a town in Wallonia, Belgium, and a district of the municipality of Charleroi. It lies in the province of Hainaut, in the country's southern, French-speaking region.
As a district of Charleroi, Gilly forms part of the larger urban area centred on that city rather than an independent municipality. It is one of several former towns and villages that were merged into Charleroi and now make up its constituent districts.
Its position within the Charleroi conurbation places it in the industrial heartland of Hainaut, a province of Wallonia in which Charleroi is the principal city.