The black hawk-eagle (Spizaetus tyrannus), also known as the tyrant hawk-eagle, is a species of eagle found from central Mexico through Central America into the south of Brazil to Colombia, eastern Peru, and as far as northern Argentina. There are two known subspecies, S.t. tyrannus, which is found in Southeastern Brazil and Northeastern Argentina, and the slightly smaller S. t. serus, which can be found elsewhere throughout the species' range. Its preferred habitats include humid and moist forests close to rivers, and several types of woodland. It is uncommon to fairly common throughout most of its range. Its closest relative is the ornate hawk-eagle, which is similar in size, appearance and behavior but lives at lower elevations.

The black hawk-eagle is 58–70 cm (23–27.5 in) long and weighs about 900 to 1,300 grams (2.0 to 2.9 pounds). It has black plumage with varying patterns on its wings and body, and white speckling in places. It has barred wings, slightly elliptical in shape, and a long, narrow tail which is rarely fanned. The four grey bars on the tail are distinctive to the black hawk-eagle, as is the white line seen slightly above the bird's eye. While flying, the broadness and shortness of the wings become apparent. While in flight, the bird's tail is typically kept closed.