Mont-Saint-Aignan Population and Area (Seine-Maritime)

Mont-Saint-Aignan: Population and Area

With 20,598 inhabitants (INSEE total population in force on January 1, 2026), Mont-Saint-Aignan is the 478^th most populous town in France in 2026 and the 8^th most populous in the Seine-Maritime department, out of 707 communes. It covers 7.94 km² (22,985^th largest area in France, 306^th largest in the department), with a population density of 2,594 inhabitants per km², or 24 times the national average (110 inhabitants/km²), which ranks it 349^th in France for density.

Mont-Saint-Aignan is located in the Seine-Maritime department (76), in the Normandy region (formerly Upper Normandy), where it ranks 14^th by population out of 2,644 communes. The most populous town in the Seine-Maritime department is Le Havre (168,588 inhabitants); the department is home to 1,281,667 people over 6,278 km².

See the full ranking of communes in the Seine-Maritime department and the regional ranking: largest city in Normandy.

Towns of similar size in the Seine-Maritime department: Dieppe (pop. 28,970), Le Grand-Quevilly (pop. 25,999), Le Petit-Quevilly (pop. 22,477), Fécamp (pop. 17,635), Montivilliers (pop. 15,684), Elbeuf (pop. 15,581).

Sources: INSEE, official population figures in force on January 1, 2026 (total population); areas: IGN / Observatoire des territoires; INSEE code 76451. Rankings are calculated across the 34,858 communes of metropolitan and overseas France in our database.