A new gyracanthid Gyracanthides riniensis is described from the Famennian (latest Devonian) Waterloo Farm Lagerstätte in the Witpoort Formation, near Makhanda/Grahamstown, South Africa. The new species is based on disarticulated remains including pectoral, pelvic, and median fin spines, endoskeletal shoulder girdle elements, and squamation patches preserved on or close to the same bedding plane. The new taxon is distinguished by having a relatively large, ornate median spine, and arrowhead-shaped tubercular ornament on the spine ridges. The species shows closest resemblance in pectoral spine proportions to Gyracanthides murrayi from the earliest Carboniferous of Australia, and in spine tubercular ornament to its Laurussian contemporary “Gyracanthus” sherwoodi. It differs in spine proportions and ornament from the older (Givetian) and younger (early Carboniferous) gyracanthids found in nearby localities.