Resident Population in Ontario County, NY was 113.01200 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Ontario County, NY reached a record high of 113.01200 in January of 2024 and a record low of 78.84900 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Ontario County, NY - last updated from the United States Federal Reserve on September of 2025.