A legally defined specific term, Região Metropolitana de São Paulo (RMSP), one definition for Metropolitan São Paulo, consists of 39 municipalities, including the state capital, São Paulo.

[2] The RMSP of São Paulo is known as a financial and economic centre of Brazil, with a total population of 20,743,587 inhabitants (2022 census[3]).

The largest municipalities are São Paulo, with a population of 11,451,245, Guarulhos with a population of 1,291,784 people, plus several municipalities with more than 500,000 inhabitants, such as São Bernardo do Campo (810,729 inh.)

It has more than 33 million inhabitants, which is 75% of the population of the entire state of São Paulo, and consists of the contiguous entities: Being the most industrialized region of the country as well as the most populated, the transportation plays an important role.

The main highways (rodovias) of the area are: The São Paulo Metro and the Companhia Paulista de Trens Metropolitanos provide rail-based transit within the metropolitan area.