The Barcelona Metropolitan Area (AMB) is the public administration of the metropolitan area of Barcelona, which occupies 636 km² and encompasses 36 municipalities with more than 3.2 million inhabitants.

The metropolitan area is a territorial, social, demographic, economic and cultural entity formed during the last century as a product of the growth and connection of urban systems around the city of Barcelona. This is the largest metropolitan conurbation in the western Mediterranean, which generates half of the GDP in Catalonia.

The new public metropolitan administration replaces the three entities existing until 2011: Mancomunitat de Municipis de l'Àrea Metropolitana de Barcelona  (Union of Municipalities of the Metropolitan Area of Barcelona), Environmental Agency and Transport Metropolitan Agency. This new AMB rationalises and simplifies the metropolitan governance by creating a single administration.