The Oesling or Ösling (Luxembourgish: Éislek) is a region covering the northern part of both the Grand Duchy of Luxembourg and Eifelkreis Bitburg-Prüm, within the greater Ardennes area that also covers parts of Belgium and France. The Oesling covers 32% of the territory of Luxembourg; to the south of the Oesling lies the Gutland (literally "Good Land"), which covers the remaining 68% of the Grand Duchy as well as the southern part of the Eifelkreis Bitburg-Prüm.
The region is characterised by hills and large deciduous forests. Almost all of Luxembourg's tallest hills are in the Oesling, particularly in the north and north-west, near the borders with Belgium and Germany. Its main hill chains are cut by scenic river valleys, most notable those of the Clerve, Our, upper Sauer, and Wiltz.
The Oesling is sparsely populated, with few larger towns; Clervaux, Vianden and Wiltz are the largest ones in the Luxembourgish part of the Oesling, of which only Wiltz has a population of over 4,816 people. Instead, the area is known for its numerous picturesque hill-side villages, which rely upon the visitors that the tourist season brings.
In the 2004 legislative election, the Free Party of Luxembourg, a small regionalist party based in the Oesling and led by local personality Jean Ersfeld, offered candidates, but none were elected. The party had difficulty in continuing to organize after the election.