Sowerby's beaked whales are found only in the North Atlantic. Their distribution is poorly known, as few at-sea sightings have been confirmed. From these limited data and shore stranding locations, they are considered to be the most northern North Atlantic species of the genus Mesoplodon (beaked whales), and range offshore from Cape Cod to Davis Strait in the western Atlantic, and from Norway to Spain in the eastern Atlantic. In the mid-Atlantic the species ranges from Iceland to the Azores and Madeira.

This species is most often sighted in deep water, along the continental shelf edge and slope. Sowerby's beaked whales are only rarely seen in coastal waters.

The Sowerby's beaked whale is a small- to medium-sized toothed whale of the family Ziphiidae. An adult Sowerby's beaked whale is typically 4.5-5.5 m long and dark grey in colour. They have a small head with a long, narrow beak and a small triangular dorsal fin approximately 2/3's of the way back from the beak to flukes. Their tail flukes generally have no center notch, and they have relatively long pectoral fins.