cabecera (county seat) and partido (county) of Gran (Greater) Buenos Aires, eastern Argentina. It lies immediately south of the city of Buenos Aires, in Buenos Aires provincia (province). The name and origin of the county and county seat date from the late 16th century, when Juan de Zamora, one of the founders of Buenos Aires, was granted a large landholding on the lomas (“slopes”) in the vicinity. In 1865 the Church of Our Lady of Peace was built in Lomas de Zamora. The national normal school was founded there in 1902, and the National University of Lomas de Zamora (1972) is located in the city.

Prior to 1910, when it was given city status, Lomas de Zamora was a residential town with a large British colony. Since 1940 it has become an industrial centre, with chemical, electrical-manufacturing, and cement industries. The county seat and county are completely within the Gran Buenos Aires urban area. Pop. (2001) city, 111,897; county, 591,345.