Marchin (; ) is a municipality of Wallonia located in the province of Liège, Belgium.
On January 1, 2006, Marchin had a total population of 5,114. The total area is 30.00 km<sup>2</sup> which gives a population density of 170 inhabitants per km<sup>2</sup>.
The municipality consists of the following districts: Marchin, and Vyle-et-Tharoul.