Pulaski County is a county in the U.S. state of Arkansas. With a population of 399,125 as of the 2020 United States Census, it is the most populous county in Arkansas. The county is included in the Little Rock–North Little Rock–Conway metropolitan area. Its county seat is Little Rock, which is also Arkansas's capital and largest city. Pulaski County is Arkansas's fifth county, formed on December 15, 1818, alongside Clark and Hempstead Counties.