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.

Edinburg is a city in and the county seat of Hidalgo County, Texas, United States. The population was 100,243 at the 2020 census, and in 2022, its estimated population was 104,294, making it the second-largest city in Hidalgo County, and the third-largest city in the larger Rio Grande Valley region.