Rio Grande City is a city located in Starr County, Texas, United States. It is the county seat and largest city in Starr County. The city is situated along the Rio Grande, which forms the border between the United States and Mexico. Rio Grande City has a diverse population, with a mix of Hispanic, White, and African American residents. The city is known for its rich history, including its role in the Mexican-American War and its importance as a trading center along the Rio Grande. It is also home to the Rio Grande City Consolidated Independent School District and several historical landmarks, such as the Starr County Courthouse.