Barretos is a municipality in the northern part of the state of São Paulo, Brazil. The city has approximately 112,101 inhabitants (IBGE/2010) and an area of 1565.6 km². Barretos belongs to the Mesoregion of Ribeirão Preto.
The city was founded on August 25, 1854. The first chapel was built in 1856, where today lies the "Praça Francisco Barreto". In January 8, 1897, Barretos was officially established as a municipality.
The tertiary sector of the city is the most relevant, with 72.09% of the city GDP. Industry is 21.64% of the GDP, and the primary sector corresponds to 6.28%. The largest Latin American cancer center is based in this city.
Barretos hosts annually the most famous rodeo festival in the country, the Festa do Peão de Barretos. The city is the seat of the Roman Catholic Diocese of Barretos.
Barretos is served by Chafei Amsei Airport.