The long-finned pilot whale has a large, bulbous forehead and a long, robust body, which can measure up to 6.3 metres in length. The prominent dorsal fin is wide at the base and deeply curved. This species of pilot whale has very long, tapered pectoral fins that can measure about a quarter of the body length. Males are usually much larger than females and they commonly have a more hooked dorsal fin and the melon may overhang the short beak. Long-finned pilot whales are mostly black or dark grey. A light coloured saddle-patch is usually present behind the dorsal fin on Northern hemisphere animals. There is a light grey anchor-shaped marking on the chest which extends as a narrow stripe down the belly.
In the Northern hemisphere their range is restricted to the north Atlantic Ocean, the North Sea and the western Mediterranean, from the Azores to Greenland. They favour deep waters, although their seasonal movements may reflect prey distribution. Sightings in the Hebrides are frequent, and the long finned pilot whale is also the most commonly stranded species here.