Resident Population in Washington County, IN was 28.20500 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Washington County, IN reached a record high of 28.29700 in January of 2010 and a record low of 19.27800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Washington County, IN - last updated from the United States Federal Reserve on May of 2024.