Resident Population in Maricopa County, AZ was 4585.87100 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Maricopa County, AZ reached a record high of 4585.87100 in January of 2023 and a record low of 971.22800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Maricopa County, AZ - last updated from the United States Federal Reserve on May of 2024.