Lee County is a county located in the U.S. state of Arkansas. With its eastern border formed by the Mississippi River, it is considered to be part of the Arkansas Delta. As of the 2020 census, the population was 8,600. The county seat is Marianna.

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."