The Maas (Dutch: Maas; IPA: [ˈmaːs];) or Meuse ( /ˈmjuːz/; French: [møz]; Walloon Mouze /muːs/) is a major European river, rising in France and flowing through Belgium and the Netherlands before draining into the North Sea. It has a total length of 925 km (575 mi).

From 1301 the upper Meuse roughly marked the western border of the Holy Roman Empire with the Kingdom of France, after Count Henry III of Bar had to receive the western part of the County of Bar (Barrois mouvant) as a French fief from the hands of King Philip IV. The border remained stable until the annexation of the Three Bishoprics Metz, Toul and Verdun by King Henry II in 1552 and the occupation of the Duchy of Lorraine by the forces of King Louis XIII in 1633. Its lower Belgian (Walloon) portion, part of the sillon industriel, was the first fully industrialized area in continental Europe.

The name Meuse is derived from the French name of the river, which evolved from the Latin name Mosa. The Dutch name Maas descends from Middle Dutch Mase, which comes from the presumed but unattested Old Dutch form *Masa, from Proto-Germanic *Masō. Only modern Dutch preserves this Germanic form, however.

Meuse (French pronunciation: [møz]) is a department in northeast France, named after the River Meuse.

Meuse is one of the original 83 departments created during the French Revolution on March 4, 1790. It was created from the former provinces of Barrois (area of Bar-le-Duc) and Three Bishoprics (area of Verdun).

The department was one of the great battlefields of World War I; an important battle was fought in 1916 at Verdun.

Meuse is part of the current region of Lorraine and is surrounded by the French departments of Ardennes, Marne, Haute-Marne, Vosges, Meurthe-et-Moselle, and Belgium on the north. Parts of Meuse belong to Parc naturel régional de Lorraine.

The important rivers are the following:

The population has decreased sharply since the 19th century, with the rural exodus to the cities.