Jacinto City is a city in Harris County, Texas, United States, east of the intersection of Interstate 10 and the East Loop of Interstate 610. Jaci…Jacinto City is a city in Harris County, Texas, United States, east of the intersection of Interstate 10 and the East Loop of Interstate 610. Jacinto City is part of the Houston–Sugar Land–Baytown metropolitan area and is bordered by the cities of Houston and Galena Park. The population was 9,613 at the 2020 census.