Oise, a department of northern France, three-fourths of which belonged to tle-de-France and the rest to Picardy, bounded N. by Somme, E. by Aisne, S. by Seine-et-Marne and Seine-etOise, and W. by Eure and Seine-Inferieure. Pop. (1906) 410,049; area 2272 sq. m. The department is a moderately elevated plateau with pleasant valleys and fine forests, such as those of Compiegne, Ermenonville, Chantilly and Halatte, all in the south-east. It belongs almost entirely to the basin of the Seine - the Somme and the Bresle, which flow into the English Channel, draining but a small area. The most important river is the Oise, which flows through a broad and fertile valley from north-east to south-west, past the towns of Noyon, Compiegne, Pont St Maxence and Creil. On its right it receives the Breche and the Therain, and on its left the Aisne, which brings down a larger volume of water than the Oise itself, the Authonne, and the Nonette, which irrigates the valley of Senlis and Chantilly. The Ourcq, a tributary of the Marne, in the south-east, and the Epte, a tributary of the Seine, in the west, also in part belong to the department. These streams are separated by ranges of slight elevation or by isolated hills, the highest point (770 ft.) being in the ridge of Bray, which stretches from Dieppe to Precy-sur-Oise. The lowest point is at the mouth of the Oise, only 66 ft. above sea-level. The climate is very variable, but the range of temperature is moderate.
Clay for bricks and earthenware, sand and building-stone are among the mineral products of Oise, and peat is also worked. Pierrefonds, Gouvieux, Chantilly and Fontaine Bonneleau have mineral springs. Wheat, oats and other cereals, potatoes and sugar beet are the chief agricultural crops. Cattle are reared more especially in the western districts, where dairying is actively carried on. Bee-keeping is general. Racing stables are numerous in the neighbourhood of Chantilly and Compiegne. Among the industries of the department of manufacture of sugar and alcohol from beetroot occupies a foremost place. The manufacture of furniture, brushes (Beauvais) and other wooden goods and of toys, fancy-ware, buttons, fans and other articles in wood, ivory, bone or mother-of-pearl are widespread industries. There are also woollen and cotton mills, and the making of woollen fabrics, blankets, carpets (Beauvais), hosiery and lace (Chantilly and its vicinity) is actively carried on. Creil and the neighbouring Montataire form an important metallurgical centre. Oise is served by the Northern railway, on which Creil is an important junction, and its commerce is facilitated by the Oise and its lateral canal and the Aisne, which afford about 70 m. of navigable waterway.
There are four arrondissements - Beauvais, Clermont, Compiegne and Senlis - with 35 cantons and 701 communes. The department forms the diocese of Beauvais (province of Reims) and part of the region of the II. army corps and of the academic (educational division) of Paris. Its court of appeal is at Amiens. The principal places are Beauvais, the capital, Chantilly, Clermont-en-Beauvoisis, Compiegne, Noyon, Pierrefonds, Creil and Senlis, which are treated separately. Among the more populous places not mentioned is Meru (5317), a centre for fancy-ware manufacture. The department abounds in old churches, among which, besides those of Beauvais, Noyon and Senlis, may be mentioned those at Morienval (11th and 12th centuries), Maignelay (15th and 16th centuries), Crepy-en-Valois (St Thomas, 12th, 13th and 15th centuries), St Leu d'Esserent (mainly 12th century), Tracy-le-Val (mainly 12th century), Villers St Paul (12th and 13th centuries), St Germer-de-Fly (a fine example of the transition from Romanesque to Gothic architecture), and St Martin-aux-Bois (13th, 14th and 15th centuries). Pontpoint preserves the buildings of an abbey founded towards the end of the 14th century and St Jean-aux-Bois the remains of a priory including a church of the 13th century. There are Gallo-Roman remains of Champlieu close to the forest of Compiegne. At Ermenonville there is a chateau of the 17th century where Rousseau died in 1778.