Mettet (; ) is a municipality of Wallonia located in the province of Namur, Belgium.
On 1 January 2006 Mettet had 11,977 inhabitants. The total area is 116.78 km<sup>2</sup>, giving a population density of 103 inhabitants per km<sup>2</sup>.
The municipality consists of the following districts: Biesme, Biesmerée, Ermeton-sur-Biert, Furnaux, Graux, Mettet, Oret, Saint-Gérard, and Stave.
In Mettet there is a race track, Circuit Jules Tacheny Mettet, for motorbikes and cars.