The female is considerably larger than the male. Adults have a red eye and black cap that contrasts with a blue-gray back and upperwings. The white breast, belly and underwings are marked by fine, thin, reddish bars. The undertail coverts are white. The tail is blue-gray above and pale below with barred black bands. The female tends to be a little browner than the male. Immature birds have a yellow eye. They are brown with white underparts marked with thin black streaks that are concentrated on the chest. On some individuals the face has an indistinct pale eyebrow. The tail is brown above and pale below with barred dark bands. The terminal tail band is white. The Cooper’s Hawk is very similar to a Sharp-shinned Hawk (Accipter striatus) but Sharp-shinned Hawks are typically smaller, with shorter, squared-off tails and shorter heads that do not project as far when flying. Immature Sharp-shinneds have thicker, denser streaking that extends farther down the belly and a thinner terminal band of white. Adults have less well-defined caps.

They are brown with white underparts marked with thin black streaks that are concentrated on the chest. On some individuals the face has an indistinct pale eyebrow. The tail is brown above and pale below with barred dark bands. The terminal tail band is white. The Cooper’s Hawk is very similar to a Sharp-shinned Hawk (Accipter striatus) but Sharp-shinned Hawks are typically smaller, with shorter, squared-off tails and shorter heads that do not project as far when flying. Immature Sharp-shinneds have thicker, denser streaking that extends farther down the belly and a thinner terminal band of white. Adults have less well-defined caps.