Wasserbillig (Luxembourgish: Waasserbëlleg [vaːsɐˈbələɕ] ) is a town in the commune of Mertert, in eastern Luxembourg. As of 2024[update], Wasserbillig has 3,485 inhabitants,[1] which makes it the largest town in Mertert. Wasserbillig is the administrative seat of the commune of Mertert.