Canandaigua is a city in Ontario County, New York, United States. Its population was 10,545 at the 2010 census. It is the county seat of Ontario County; some administrative offices are at the county complex in the adjacent town of Hopewell. The name Canandaigua is derived from the Seneca name of its historic village here, spelled variously Kanandarque, Ganandogan, Ga-nun-da-gwa, or Konondaigua, which was established long before any European Americans came to the area.