Lee County was formed on April 17, 1873, from parts of Crittenden, Monroe, Phillips and St. Francis counties. The county was named for General Robert E. Lee.

The county seat is Marianna. The landscape of Lee County is rolling hills in the northern tip and rich delta flat farmland in the center. Crowley's Ridge runs through the northern tip.

The Mississippi River makes up the eastern border of the county, and half of the St. Francis National Forest, the smallest forest in the nation, is situated in the southeastern section with excellent hunting and fishing. Altogether Lee County has 25 lakes and 320 miles of manmade shoreline. The economy is mainly agriculture. Rich cotton and other typical delta crops are grown here. The Crowley's Ridge area grows fruit crops and pecan trees. Processing agricultural products and light manufacturing has helped the economy.