The metropolis of Phoenix stands as the foremost urban center of Arizona, boasting a staggering population of 1,608,139 as of 2020. As the fifth most populous city in the United States, Phoenix stands as a testament to the growth and prosperity of the region. Additionally, it holds the distinction of being the most populous state capital in the country, and the only one that can boast of a populace exceeding one million souls.
Phoenix serves as the focal point of the Phoenix metropolitan area, colloquially referred to as the Valley of the Sun, which forms a constituent part of the Salt River Valley. As of 2020, this metropolitan area boasts a population of approximately 4.85 million individuals, thereby securing its position as the largest in the Southwestern United States and the eleventh largest nationally. Phoenix, as the county seat of Maricopa County, occupies the largest geographic expanse amongst all cities in Arizona, spanning a total area of 517.9 square miles. It is, moreover, the eleventh largest city by area in the United States. This metropolitan area, which dominates the Arizona Sun Corridor megaregion, reigns supreme as the largest megalopolis both in terms of population and landmass.