Resident Population in Hamilton County, IN was 371.64500 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Hamilton County, IN reached a record high of 371.64500 in January of 2023 and a record low of 54.53200 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Hamilton County, IN - last updated from the United States Federal Reserve on May of 2024.