Geneva is a city in Ontario and Seneca counties in the U.S. state of New York. It is at the northern end of Seneca Lake; all land portions of the city are within Ontario County; the water portions are in Seneca County. The population was 12,812 at the 2020 census. The city is supposedly named after the city and canton of Geneva in Switzerland. The main settlement of the Seneca was spelled Zoneshio by early European settlers, and was described as being two miles north of Seneca Lake.