Hieraaetus wahlbergi Wahlberg's eagle is a medium-sized raptor, and the sexes are similar. It is about 53–61 cm (21–24 in) in length with a wingspan of 130–146 cm (51–57.5 in) and a body mass of 437–845 g (15.4–29.8 oz) for males and 670–1,400 g (1.48–3.09 lb) for females on average. The head has a small crest, and the legs are yellow. The plumage tone is variable but may be dark brown except for dark-streaked grey undersides to the flight feathers, and a barred grey undertail. Light and dark plumage phases occur. A pale variant may be much lighter brown with whitish, rather than grey undertail and flight feather undersides.
While the large brown eagles are generally a tricky group to identify, Wahlberg's eagle have some distinctive features. A small, pointed crest is usually visible. The gape only extends at maximum to the middle of the eye, whereas in lesser spotted eagle, it extends to the back of the eye. Round nostrils are not present in either tawny eagles or steppe eagles, but the two spotted eagles also have round nostrils. In flight, this species is very cross-shaped, with long, evenly wide wings, a slim body, and a narrow, square-ended tail. The wings are held very flat.
In September 2019, there were reports of eagles attacking people in the Somali portion of Ethiopia. This led to an eagle being captured near Burao, in Somaliland. On 16 July 2020, images of the captured bird posted to iNaturalist were identified by three people as Hieraaetus wahlbergi. Note that there is no evidence that the captured bird had been attacking people, nor that it was the same species as those that had been attacking people in Ethiopia. The images are the basis of the occurrence record in HARG-Zoo-I.