Cinco Ranch is a census-designated place and master-planned community located in the extraterritorial jurisdiction of the city of Houston within Fort Bend and Harris counties in the U.S. state of Texas. According to the United States Census Bureau, the CDP has a total area of 4.9 square miles (12.8 km2).The population was 16,899 at the 2020 census. It lies approximately 25 miles (40 km) west of the Harris County seat of Houston and 10 miles (16 km) north of the Fort Bend County seat of Richmond. Cinco Ranch is considered to be part of the Greater Katy area and is roughly 10 miles southeast of the city of Katy.