Resident Population in Niagara County, NY was 209.45700 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Niagara County, NY reached a record high of 235.72000 in January of 1970 and a record low of 209.45700 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Niagara County, NY - last updated from the United States Federal Reserve on May of 2024.