Deer Park is a city in the U.S. state of Texas within the Houston–Sugar Land–Baytown metropolitan area. The city is located in Harris Count…Deer Park is a city in the U.S. state of Texas within the Houston–Sugar Land–Baytown metropolitan area. The city is located in Harris County and is situated in Southeast Harris County. At the 2020 U.S. census, the population of Deer Park was 34,495.