The Peregrine Falcon (Falco peregrinus), also known simply as the Peregrine, and historically as the Duck Hawk in North America, is a cosmopolitan bird of prey in the family Falconidae. It is a large, crow-sized falcon, with a blue-gray back, barred white underparts, and a black head and moustache. It can reach speeds over 322 km/h (200 mph) in a dive, making it the fastest animal in the world. As is common with bird-eating raptors, the female is much bigger than the male. Experts recognize 17–19 subspecies, which vary in appearance and range; there is disagreement over whether the distinctive Barbary Falcon is a subspecies or a distinct species.
The Peregrine's breeding range includes land regions from the Arctic tundra to the Tropics. It can be found nearly everywhere on Earth, except extreme polar regions, very high mountains, and most tropical rainforests; the only major ice-free landmass from which it is entirely absent is New Zealand. This makes it the world's most widespread bird of prey. Both the English and scientific names of this species mean wandering falcon, referring to the migratory habits of many northern populations.