Lagny-sur-Marne

Lagny-sur-Marne
The town hall of Lagny-sur-Marne
Location (in red) within Paris inner and outer suburbs
Location of Lagny-sur-Marne
Lagny-sur-Marne
Lagny-sur-Marne
Coordinates: 48°52′44″N 2°42′27″E / 48.8788°N 2.7075°E / 48.8788; 2.7075
CountryFrance
RegionÎle-de-France
DepartmentSeine-et-Marne
ArrondissementTorcy
CantonLagny-sur-Marne
IntercommunalityMarne et Gondoire
Government
 • Mayor (2020–2026) Jean-Paul Michel
Area
1
5.72 km2 (2.21 sq mi)
Population
 (2023)
21,461
 • Density3,750/km2 (9,720/sq mi)
DemonymLatignaciens
Time zoneUTC+01:00 (CET)
 • Summer (DST)UTC+02:00 (CEST)
INSEE/Postal code
77243 /77400
Elevation37–112 m (121–367 ft)
(avg. 44 m or 144 ft)
Websitewww.lagny-sur-marne.fr
1 French Land Register data, which excludes lakes, ponds, glaciers > 1 km2 (0.386 sq mi or 247 acres) and river estuaries.

Lagny-sur-Marne (French pronunciation: [laɲi syʁ maʁn] ; lit. 'Lagny-on-Marne') is a commune in the eastern outer suburbs of Paris, France. It is located in the Seine-et-Marne department in Île-de-France, 26.1 km (16.2 mi) from the centre of Paris (25 minutes by train from Gare de l'Est).

The commune of Lagny-sur-Marne is part of the Val de Bussy sector, one of the four sectors in the "new town" of Marne-la-Vallée.