Osasco is a municipality and city in São Paulo in Brazil, ranking 5th in population among São Paulo municipalities. The current mayor is Emidio Pereira de Souza (PT).
Osasco was founded by the Italian Antonio Agu (currently the name of one of the main street in Osasco). He came from a homonym commune in the province of Turin.
The population in 2003 is 678,583, the density is 10,439.74/km² and the total area is 65 km². It ranks 4th in the São Paulo metropolitan area. It's considered the major urban centre of the Western portion of the Greater São Paulo. It used to be a district of São Paulo City until February 19, 1962, when Osasco became a municipality of its own.
It is linked by CPTM rapid transit to São Paulo by the B and C train lines.