Boulogne-Billancourt

Boulogne-Billancourt
Location (in red) within Paris inner suburbs
Location of Boulogne-Billancourt
Boulogne-Billancourt
Boulogne-Billancourt
Coordinates: 48°50′07″N 2°14′27″E / 48.83520°N 02.2409°E / 48.83520; 02.2409
CountryFrance
RegionÎle-de-France
DepartmentHauts-de-Seine
ArrondissementBoulogne-Billancourt
CantonBoulogne-Billancourt-1 and 2
IntercommunalityGrand Paris
Government
 • Mayor (2020–2026) Pierre-Christophe Baguet (LR)
Area
1
6.17 km2 (2.38 sq mi)
Population
 (2023)
119,019
 • Density19,300/km2 (50,000/sq mi)
DemonymBoulonnais
Time zoneUTC+01:00 (CET)
 • Summer (DST)UTC+02:00 (CEST)
INSEE/Postal code
92012 /92100
Elevation28–40 m (92–131 ft)
1 French Land Register data, which excludes lakes, ponds, glaciers > 1 km2 (0.386 sq mi or 247 acres) and river estuaries.

Boulogne-Billancourt (French: [bulɔɲ bijɑ̃kuʁ] ; often colloquially simply Boulogne, until 1924 officially Boulogne-sur-Seine, [bulɔɲ syʁ sɛn], lit. 'Boulogne-on-Seine') is a wealthy and prestigious commune in the western inner suburbs of Paris, France, located 8.2 km (5 mi) from the centre of Paris at Notre Dame. It is a subprefecture of the Hauts-de-Seine department and thus the seat of the larger arrondissement of Boulogne-Billancourt. It is also part of the Métropole du Grand Paris. Boulogne-Billancourt includes one island in the Seine: Île Seguin.

Boulogne-Billancourt is one of the wealthiest regions in the Parisian area and in France. Formerly an important industrial site, it has successfully reconverted into business services and is now home to major communication companies headquartered in the Val de Seine business district.