The clymene dolphin is a small dolphin that averages 1.8m in length. It has a short beak, a white belly, light gray sides, and a dark cape that dips in two points above the eye and below the dorsal fin. The facial markings are very distinct, including black eye rings, dark lips and snout tip, and a dark line on top of the snouts sometimes making a "moustache" near the apex of the melon. The cape sometimes has blotchy patches on the sides, and the dorsal fin is gray but bordered with dark margins.

On average members of this species have 38 to 49 teeth on each side of the upper and lower jaws, which are slender and pointed.

Average mass: 85 kg.