Mogi Guaçu is a municipality in the state of São Paulo in Brazil. The population is 147,233 (2015 est.) in an area of 813 km².[1] The city is at an average elevation (above sea level) of 591 m. Mogi Guaçu is a place name that probably originates from the Tupi language. It means "large river of snakes".[2] The city was founded on April 9, 1877.

The municipality contains the 469 hectares (1,160 acres) Mogi-Guaçu Biological Reserve, a fully protected conservation area created in 1942.[3]

THe Autódromo Velo Cittá is a motorsport racetrack opened in 2012, located 20 km northeast of the city of Mogi Guaçu.