Monroe is an unincorporated community and census-designated place in Monroe County, Arkansas, United States. The unincorporated community extends beyond the CDP slightly into Lee County. It was first listed as a CDP in the 2020 census with a population of 51. Monroe is located at the junction of U.S. Route 79 and Arkansas Highway 39, 12 miles east-northeast of Clarendon. Monroe has a post office with ZIP code 72108.