A checklist of 131 species of robber flies from Arkansas is presented. It includes 101 species studied by the authors, of which 66 species are here recorded for the first time from the state. Seven more species have been recorded in the literature, and 23 species that might occur in the state have never been recorded. The Arkansas robber fly fauna has close affinities with the fauna of the eastern United States. Distributional notes are given for several species, and biological notes are presented for Orthogonis stygia. Ceraturgus fasciatus is resurrected from synonymy with C. cruciatus.