Phillips County is a county located in the eastern part of the U.S. state of Arkansas, in what is known as the Arkansas Delta along the Mississippi River. As of the 2020 census, the population was 16,568. The county seat is Helena–West Helena.

The Arkansas Delta is one of the six natural regions of the state of Arkansas. Willard B. Gatewood Jr., author of The Arkansas Delta: Land of Paradox, says that rich cotton lands of the Arkansas Delta make that area "The Deepest of the Deep South."