​ST OUEN, an industrial town of northern France, in the department of Seine, on the right bank of the Seine 1 m. N. of the fortifications of Paris. Pop. (1906) 37,673. A château of the early 19th century occupies the site of a château of the 17th century bought by Madame de Pompadour in 1745, where in 1814 Louis XVIII. signed the declaration promising a constitutional charter to France. Previously there existed a chateau built by Charles of Valois in the early years of the 14th century, where King John the Good inaugurated the short-lived order of the Knights of “ Notre Dame de la noble maison,” called also the “ ordre de l'étoile.” The industries of St Ouen include metal founding, engineering and machine construction and the manufacture of government uniforms, pianos, chemical products, &c. It has important docks on the Seine and a race-course.