El Paso County is one of the 64 counties of the U.S. state of Colorado. As of the 2010 census, the population was 622,263. The Census Bureau's 2014 estimate indicates it now the second most populous county in Colorado, after the City and County of Denver. The county seat is Colorado Springs, the second most populous city in Colorado.El Paso County is included in the Colorado Springs, CO Metropolitan Statistical Area.El Paso County is located in Colorado's 5th congressional district.