Spring is a census-designated place (CDP) within the extraterritorial jurisdiction of Houston in Harris County, Texas, United States, part of the metropolitan area. The population was 54,298 at the 2010 census. While the name "Spring" is applied to a large area of northern Harris County and a smaller area of southern Montgomery County, the original town of Spring, now known as Old Town Spring, is located at the intersection of Spring-Cypress and Hardy roads and encompasses a relatively small area of perhaps 1 km².