Resident Population in Galveston County, TX was 372.20700 Thous. of Persons in January of 2025, according to the United States Federal Reserve. Historically, Resident Population in Galveston County, TX reached a record high of 372.20700 in January of 2025 and a record low of 169.81200 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Galveston County, TX - last updated from the United States Federal Reserve on May of 2026.