The term Low Countries, also known as the Low Lands (Dutch: de Lage Landen, French: les Pays-Bas, Luxembourgish: déi Niddereg Lännereien) and historically called the Netherlands (Dutch: de Nederlanden), Flanders, or Belgica, is a coastal lowland region in Northwestern Europe forming the lower basin of the Rhine–Meuse–Scheldt delta and consisting of three countries: Belgium, the Netherlands and Luxembourg. Geographically and historically, the area also includes parts of France and Germany such as French Flanders and the German regions of East Frisia and Cleves. During the Middle Ages, the Low Countries were divided into numerous semi-independent principalities.

Historically, the regions without access to the sea linked themselves politically and economically to those with access to form various unions of ports and hinterland, stretching inland as far as parts of the German Rhineland. Because of this, nowadays not only physically low-altitude areas, but also some hilly or elevated regions are considered part of the Low Countries, including Luxembourg and the south of Belgium. Within the European Union, the region's political grouping is still referred to as the Benelux (short for Belgium-Netherlands-Luxembourg).

During the Roman Empire, the region contained a militarised frontier and contact point between Rome and Germanic tribes. With the fall of the Western Roman Empire, the Low Countries were the scene of the early independent trading centres that marked the reawakening of Europe in the 12th century. In that period, they rivalled northern Italy as one of the most densely populated regions of Western Europe. Guilds and councils governed most of the cities along with a figurehead ruler; interaction with their ruler was regulated by a strict set of rules describing what the latter could and could not expect. All of the regions mainly depended on trade, manufacturing and the encouragement of the free flow of goods and craftsmen. Dutch and French dialects were the main languages used in secular city life.