Carrollton is a city in Dallas, Denton, and Collin counties in the U.S. state of Texas. As of the 2020 census, its population was 133,434, makin…Carrollton is a city in Dallas, Denton, and Collin counties in the U.S. state of Texas. As of the 2020 census, its population was 133,434, making it the 27th-most populous city in Texas. The area was first settled by Jared Ford in 1842 by William and Mary Larner on a site within the Peters Colony grant. In 1844, the A. W. Perry family claimed land in the area around Trinity Mills where, in partnership with Wade H. Witt, a mill was established.