A new eureptile, Concordia cunninghami, gen. et sp. nov., is described from the Upper Pennsylvanian Hamilton-Fossillagerstätte, Kansas, U.S.A. The new taxon is currently known on the basis of two well-preserved skulls. A phylogenetic analysis groups Concordia consistently with captorhinids; the holotype, therefore, can be regarded as the oldest record of a captorhinid reptile, and the first one from the Carboniferous. Concordia reduces to a notable extent the stratigraphic gap between captorhinids and the first appearance of other eureptiles. Furthermore, the new taxon is the third known amniote representative from the Hamilton fauna, improving our knowledge of Late Carboniferous terrestrial communities.