Resident Population in McMullen County, TX was 0.56500 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in McMullen County, TX reached a record high of 1.10000 in January of 1972 and a record low of 0.56500 in January of 2024. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in McMullen County, TX - last updated from the United States Federal Reserve on April of 2026.