Neuchâtel, canton, western Switzerland, bordering France to the northwest and Lake Neuchâtel to the southeast and bounded by the cantons of Bern on the northeast and Vaud on the southwest. It lies in the central Jura Mountains and is drained by Lake Neuchâtel (leading to the Rhine) and Le Doubs River (leading to the Rhône). Its three regions are a low-lying strip along the lake called Le Vignoble (from its vineyards); an intermediate region, Les Vallées, comprising the two principal valleys of the canton (the Ruz Valley, watered by the Seyon, and the Travers Valley, watered by L’Areuse), which lie at an elevation of 2,300 feet (700 metres); and the highest region, the Neuchâteloises Mountains (3,000–3,500 feet [915–1,065 metres]), mainly composed of a long valley in which stand the industrial centres of La Chaux-de-Fonds, Le Locle, La Sagne, Les Ponts-de-Martel, and La Brévine. Neuchâtel is the capital.
Novum Castellum (Neuchâtel) was first mentioned in the will of Rudolf III, the last king of Burgundy, who died in 1032. About 1034 the town and its territories were granted in fief to Count Ulrich von Fenis, whose dynasty gradually increased its dominion, until by 1373 it held practically all the area of the present canton. In 1406 Neuchâtel entered into union with Bern. It passed in the early 15th century to the lords of Freiburg im Breisgau in the German Rhineland and in 1504 to the French ducal house of Orléans-Longueville. The Reformation was introduced there in 1530 by Guillaume Farel, the French preacher, and Neuchâtel became a principality in 1648. With the extinction of the house of Orléans-Longueville in 1707, the area passed to Frederick I, the first king of Prussia. The nominal role of the Prussian king lasted until 1848, with a brief interval from 1806 to 1814 when the principality was granted by Napoleon to his marshal, Louis-Alexandre Berthier. It was admitted to the Swiss Confederation in 1815 as the 21st canton and the only nonrepublican member, its hereditary rulers the last to maintain their position in Switzerland. A republican form of government was established by a peaceful revolution in 1848, and after long negotiations and several attempts at counter-revolution, including the so-called Neuchâtel crisis (1856), the king of Prussia renounced his claims to sovereignty in 1857.
The population is mainly French speaking and has a Protestant majority. In addition to excellent wineries, some fruit is grown in Le Vignoble, and horses are raised. There are pastures for cattle in the valleys, and some cheese is made. The most valuable mineral product is asphalt, concentrated in the Travers Valley. The most characteristic industry is watchmaking, which has been prominent since the early 18th century in the highland valleys of La Chaux-de-Fonds, Le Locle, and Fleurier; in 2009 La Chaux-de-Fonds and Le Locle together were designated a UNESCO World Heritage site. Other important manufactures include metal products, machines, and tobacco products. An oil refinery is located at Cressier. Road and rail communications are highly developed. Area 310 square miles (803 square km). Pop. (2007 est.) 168,912.