Lanús is a partido in Buenos Aires Province, Argentina, at the south of the Gran Buenos Aires urban conglomerate neighbouring Buenos Aires city.
The partido has an area of 45 km2, and a population of 453,500. Its capital is the city of Lanús.
Lanús Partido is connected to the Buenos Aires city across the Valentín Alsina Bridge over the Riachuelo River. The name of the partido comes from the former land owner Anacarsis Lanús, who was a pioneer in the urbanization of the area.
