McAllen is a city in the U.S. state of Texas and the most populous city in Hidalgo County. It is located at the southern tip of the state in the Rio Grande Valley, on the Mexico–United States border. The city limits extend south to the Rio Grande, across from the Mexican city of Reynosa. McAllen is about 70 mi (110 km) west of the Gulf of Mexico. As of the 2020 census, McAllen's population was 142,210, making it the 23rd-most populous city in Texas. It is the fifth-most populous metropolitan area (McAllen–Edinburg–Mission) in the state of Texas, and the binational Reynosa–McAllen metropolitan area counts a population of more than 1.5 million.

Hidalgo County is located in the U.S. state of Texas. The county seat is Edinburg and the largest city is McAllen. The county is named for Miguel Hidalgo y Costilla, the priest who raised the call for Mexico's independence from Spain. It is located in the Rio Grande Valley of South Texas and is one of the fastest-growing counties in the United States. As of the 2020 census, its population was 870,781, making it the ninth-most populous county in Texas, and the most populous county outside of the counties in the Texas Triangle. Hidalgo County is designated by the U.S. Census Bureau as the McAllen–Edinburg–Mission metropolitan statistical area, which itself is part of the McAllen-Edinburg-Mission-Rio Grande City, Texas combined statistical area with neighboring Starr County.