Phillips County is a county located in the U.S. state of Arkansas. As of 2010, the population was 21,757. The county seat is Helena-West Helena. Phillips County is Arkansas's seventh county, formed on May 1, 1820, and named for Sylvanus Phillips, the area's first-known white settler and representative to the first Territorial Legislature of the Arkansas Territory. The Helena-West Helena Micropolitan Statistical Area includes all of Phillips County.