Conroe is a city in and the county seat of Montgomery County, Texas, United States, about 40 miles north of Houston. It is a principal city i…Conroe is a city in and the county seat of Montgomery County, Texas, United States, about 40 miles north of Houston. It is a principal city in the Houston–The Woodlands–Sugar Land metropolitan area. As of 2023, the population was 103,035. Since 2007, the city has increased in size by annexation, with the city territory expanding from 52.8 to 74.4 square miles. Some communities have attempted to fight such annexation. According to the Census Bureau, Conroe was the fastest-growing large city in the United States between July 1, 2015, and July 1, 2016.