Despite the similar British common names, they are not so closely related to the Cepphus guillemots, which form the tribe Cepphini.

Some prehistoric Uria species are also known: U. brodkorbi is notable insofar as it is the only known occurrence of the Alcini tribe in the temperate to subtropical Pacific, except for the very fringe of the range of U. aalge.

They dive for food from the surface, swimming underwater and being among the deepest divers of all birds, using their stubby wings to routinely dive to more than 100 meters, and feeding on fish and crustaceans, also some molluscs, insects and plant material.

[7] Adult birds are black or brown on the head, neck, back and wings with white underparts.

Uria guillemots produce a variety of harsh cackling calls at the breeding colonies, but are silent at sea.