Maricopa County Quick Facts

  1. Population
  2. Land
  3. History
  4. County Seal


  • The nation’s 4th largest county in terms of population
  • 2018 population of 4.4 million people, according to U.S. Census Bureau
  • Makes up more than half of Arizona’s population
  • Fastest-growing county in the United States, with more than 81,000 people added between July 2017-2018