Waldron is a city in Scott County, Arkansas, United States. Its population was 3,386 at the 2020 census. The city is the county seat of Scott County. Waldron was platted in 1845 by surveyor W. P. Waldron, and named for him. A post office called Waldron has been in operation since 1846. Waldron was incorporated in 1875. Waldron was reached by the Arkansas Western Railroad from Heavener, Oklahoma in 1901. Later called the Arkansas Western Railway, a subsidiary of and subsequently incorporated into the Kansas City Southern, the line is now leased to and operated by the Arkansas Southern Railroad.