
Phoenix is the capital and most populous city of the U.S. state of Arizona, with 1,608,139 residents as of 2020. It is the fifth-most populous city in the United States, and one of only two U.S. state capitals with a population of more than one million residents, along with Austin, Texas.
Phoenix is the anchor of the Phoenix metropolitan area, also known as the Valley of the Sun, which in turn is part of the Salt River Valley. The metropolitan area is the 11th largest by population in the United States, with approximately 4.85 million people as of 2020. Phoenix, the seat of Maricopa County, has the largest area of all cities in Arizona, with an area of 517.9 square miles, and is also the 11th largest city by area in the United States. It is the largest metropolitan area, both by population and size, of the Arizona Sun Corridor megaregion.