Gorostiaga is a town located in the Chivilcoy Partido in the province of Buenos Aires, Argentina.
Gorostiaga was founded as a town on September 11, 1910, from part of the lands subdivided from a female landowner following her death. A railway station had already been built in the town 50 years prior in 1866 by the Ferrocarril Oeste. Plans for the creation of a town had been proposed as early as 1904 by the heirs of the owners of the land that would become Gorostiaga. Passenger rail service to the town ended in 2015.
According to INDEC, which collects population data for the country, the town had a population of 386 people as of the 2001 census.