Resident Population in Brazoria County, TX was 398.93800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Brazoria County, TX reached a record high of 398.93800 in January of 2023 and a record low of 108.31200 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Brazoria County, TX - last updated from the United States Federal Reserve on May of 2024.