The thornback ray (Raja clavata), or thornback skate, is a species of ray fish in the family Rajidae.

The Thornback ray is found in the Atlantic coastal waters of Europe and western Africa. It is also present from South Africa to the southwestern Indian Ocean and in the Mediterranean and Black Seas. It is native possibly as far south as Namibia and South Africa.

Its natural habitats are open large seas and shallow seas. It is sometimes seen trapped in large estuarine pools at low tide.

The thornback ray is probably one of the most common rays encountered by divers.

The thornback ray is usually found on sedimentary seabeds such as mud, sand or gravel at depths between 10 and 60 m. Juvenile fish feed on small crustaceans, particularly amphipods and bottom-living shrimps; adults feed on crabs, shrimps and small fish.

The thornback ray is a demersal species and has been found from inshore to 300 metres (980 ft). More infrequently it has been found as deep as 1,020 metres (3,350 ft).

Like all rays, the thornback ray has a flattened body with broad, wing-like pectoral fins. The body is kite-shaped with a long, thorny tail. The back is covered in numerous thorny spines, as is the underside in older females. The upper and lower jaws have between 36-44 rows.

Adult fish can grow to 1 metre (3.3 ft) in length, although most are less than 85 centimetres (33 in). This ray can weigh from 4.5 to 8.75 lb (2 to 4 kg).