New Braunfels is a city in Comal and Guadalupe counties in the U.S. state of Texas. It is the seat of Comal County. The city covers 44.9 square …New Braunfels is a city in Comal and Guadalupe counties in the U.S. state of Texas. It is the seat of Comal County. The city covers 44.9 square miles and had a population of 90,403 as of the 2020 Census. A suburb just north of San Antonio, and part of the Greater San Antonio metropolitan area, it was the third-fastest-growing city in the United States from 2010 to 2020. As of 2022, the U.S. Census Bureau estimates its population at 104,707.