Duffel is a municipality in the Belgian province of Antwerp.

Antwerp Province, between 1815 and 1830 known as Central Brabant, is the northernmost province both of the Flemish Region, also called Flanders, and of Belgium. It borders on the North Brabant province of the Netherlands to the north and the Belgian provinces of Limburg, Flemish Brabant and East Flanders. Its capital is Antwerp, which includes the Port of Antwerp, the second-largest seaport in Europe. It has an area of 2,876 km2 (1,110 sq mi), and with over 1.85 million inhabitants as of January 2019, is the country's most populous province. The province consists of three arrondissements: Antwerp, Mechelen and Turnhout. The eastern part of the province comprises the main part of the Campine region.