Martelange (French pronunciation: [maʁtəlɑ̃ʒ]; German: Martelingen; Luxembourgish: Maartel pronounced [ˈmaːtəl] ⓘ; Walloon: Måtlindje) is a municipality of Wallonia located in the province of Luxembourg, Belgium.

For some 1.8 kilometres (1.1 mi), the N4 Brussels to Arlon road, which passes through the village, forms the border with the Grand Duchy of Luxembourg.

Because fuel, tobacco, and alcohol taxes are lower in Luxembourg than in Belgium, the eastern, Luxembourgish side of this stretch of road has become lined with numerous petrol stations and liquor stores.

Between 1830 and 1947, the town was a major slate quarrying centre, though the industry has now completely disappeared.

On August 21, 1967, a French tanker lorry containing 45 000 litres of Liquefied petroleum gas suffered from failing brakes while driving downhill.