About Kyle, TX. Kyle, Texas, one of the fastest-growing cities in the United States, is poised to become the largest city in Hays County in the coming years and is currently ranked as the second fastest-growing city with a population of over 50,000 in the nation. With over 62,500 residents, Kyle’s rapid development and its location in the heart of the Texas Innovation Corridor make it an ideal place to live, work, and play. Kyle’s growth is power...