Mechanicville is a city in Saratoga County, New York, United States. The population was 5,019 at the 2000 census. The name is derived from the occupations of early residents. The city is located on the eastern border of Saratoga County and is north of Albany, the state capital. Mechanicville borders the towns of Stillwater (of which it was once a part) and Halfmoon in the county, and the town of Schaghticoke, in Rensselaer County.