Mesa ( MAY-sə) is a city in Maricopa County, in the U.S. state of Arizona. It is a suburb about 20 miles (32 km) east of Phoenix in the East Valley section of the Phoenix Metropolitan Area. It is bordered by Tempe on the west, the Salt River Pima-Maricopa Indian Community on the north, Chandler and Gilbert on the south along with Queen Creek, and Apache Junction on the east.
Mesa is the largest suburban city by population in the United States, the third-largest city in Arizona after Phoenix and Tucson, the 37th-largest city in the US, and the largest city that is not a county seat. The city is home to 504,258 people as of 2020 according to the Census Bureau, which makes it more populous than Minneapolis, St. Louis, and Miami. Mesa is home to numerous higher education facilities including the Polytechnic campus of Arizona State University. It is also home to the largest relief airport in the Phoenix area, Phoenix-Mesa Gateway Airport, which is in the southeastern corner of the city.