Eagles are very large birds of prey. They are members of the bird order Falcon. Eagles have a more powerful build than other birds of prey, and they have a heavier head and bill. Even the smallest eagles, like the Booted Eagle (which is similar in size to a Common Buzzard or Red-tailed Hawk), have relatively longer and more evenly broad wings, and more direct, faster flight.

Most eagles are larger than any birds of prey apart from the vultures and kites. Like all birds of prey, eagles have very large powerful hooked beaks for tearing flesh from their prey, strong legs, and powerful talons. They also have extremely keen eyesight to enable them to spot potential prey from a very long distance. This keen eyesight is primarily contributed by their extremely large pupils.