The Cooper's Hawk (Accipiter cooperii) is a medium-sized hawk.

They are permanent residents in most of the United States and their breeding range from Southern Canada to Northern Mexico. They are generally distributed more to the South than the other North American Accipiters, the Sharp-shinned Hawk and the Northern Goshawk. Northern birds migrate to the southern limits of their range (down to as far south as Panama).

The average adult male, at 312 g (11 oz), 39 cm (15 in) long and a wingspan of 73 cm (29 in), is considerably smaller than the female, at 500 g (1.1 lb), 45 cm (18 in) long and a wingspan of 83 cm (33 in). Adults have short broad wings and a long round-ended tail with dark bands. They have a dark cap, blue-grey upperparts and white underparts with red bars. They have red eyes and yellow legs. This bird is somewhat larger than a Sharp-shinned Hawk and smaller than a Northern Goshawk, though size is blurred between larger individuals of the previous species and small males of the latter. It appears long-necked in flight and has been described by birdwatchers as looking like a "flying cross".

These birds capture prey from cover or while flying quickly through dense vegetation, relying almost totally on surprise. Most prey are mid-sized birds, with typical prey including American Robins, jays, piciforms, starlings, icterids and doves. Birds preyed on can range in size from wood-warblers to Ring-necked Pheasants. They also eat small mammals, especially rodents like chipmunks and tree squirrels. Mammalian prey can be as small as mice and as large as hares. Other possibilities are lizards, frogs, snakes and large insects. They often pluck the feathers off their prey on a post or other perch. They are increasingly seen hunting smaller songbirds in backyards with feeders. They will perch in trees overlooking the backyard feeders, then swoop down and scatter the other birds in order to capture one in flight.

Their breeding habitat are forested areas. The breeding pair builds a stick nest in large trees. The clutch size is usually 3 to 5 eggs. The cobalt eggs average at about 48 x 38 mm (1.9 x 1.5 in) and weigh about 43 g (1.5 oz). The incubation period can range from 30 to 36 days. The hatchlings are about 28 g (1 oz) and 9 cm (3.8 in) long and are completely covered in white down. The offspring are brooded for about two weeks by the female, while her mate forages for food. The fledging stage is reached at 25 to 34 days of age, though the offspring will return to the nest to be fed for up to 4 more weeks. Eggs and nestlings are preyed on, rarely, by raccoons, crows and competing Cooper's Hawks. Adults rarely fall prey to Red-tailed Hawks, Great Horned Owls and Northern Goshawks.

At one time, Cooper's Hawks were heavily hunted in persecution for preying on poultry and were called "chicken hawks". We now know that predation by these hawks on domestic animals borders on negligible and they are rarely hunted these days. Cooper's Hawks were also effected in breeding success by the use of the pesticide DDT, but the banning of usage curbed that issue. After these two threats, the adaptable Cooper's Hawk has thrived.

This bird was named after the naturalist William Cooper, one of the founders of the American Museum of Natural History in New York.