Aulnay-sous-Bois Population and Area (Seine-Saint-Denis)

Aulnay-sous-Bois: Population and Area

With 87,951 inhabitants (INSEE total population in force on January 1, 2026), Aulnay-sous-Bois is the 53^rd most populous town in France in 2026 and the 4^th most populous in the Seine-Saint-Denis department, out of 39 communes. It covers 16 km² (10,981^st largest area in France, 2^nd largest in the department), with a population density of 5,429 inhabitants per km², or 50 times the national average (110 inhabitants/km²), which ranks it 126^th in France for density.

Aulnay-sous-Bois is located in the Seine-Saint-Denis department (93), in the Île-de-France region, where it ranks 12^th by population out of 1,266 communes. The most populous town in the Seine-Saint-Denis department is Saint-Denis (149,936 inhabitants); the department is home to 1,710,659 people over 236 km².

See the full ranking of communes in the Seine-Saint-Denis department and the regional ranking: largest city in Île-de-France.

Towns of similar size in the Seine-Saint-Denis department: Saint-Denis (pop. 149,936), Montreuil (pop. 112,549), Aubervilliers (pop. 88,529), Noisy-le-Grand (pop. 73,408), Drancy (pop. 72,583), Le Blanc-Mesnil (pop. 62,547).

Sources: INSEE, official population figures in force on January 1, 2026 (total population); areas: IGN / Observatoire des territoires; INSEE code 93005. Rankings are calculated across the 34,858 communes of metropolitan and overseas France in our database.

Aulnay-sous-Bois, a major city in eastern Seine-Saint-Denis

Aulnay-sous-Bois ranks among the most populous towns in Seine-Saint-Denis without being either the prefecture or a subprefecture. Its territory, larger than that of most towns in the inner ring, explains a more moderate density than that of its neighbors closer to Paris.

Two towns in one

In the south, the old village and its neighborhoods of detached houses, served by the RER B, recall the rural market town that Aulnay-sous-Bois was before the railroad arrived. In the north, the large housing projects built in the 1960s and 1970s took in thousands of families who came to work in the industries of the eastern Paris area, including the PSA car plant, which closed in 2014. It is this twofold growth, first residential and then industrial, that lifted the town into the ranks of France's major cities. After the plant closed, its vast site became one of the major redevelopment projects in northeastern Île-de-France.