The Great Horned Owl is the most common and widespread large owl found in the Americas. Its range spans much of the New World from the Arctic tundra to the tip of South America. A variety of subspecies are recognized based on regional differences in size and color. Throughout its range, this owl has adapted to many different habitats and climates from temperate forests, tropical rainforests, and deserts to agricultural fields and urban parks, but it is generally more common in open, fragmented areas than in dense primary forests.

The Great Horned Owl is characterized by prominent ear tufts or "horns" from which it derives its name. It has large yellow eyes surrounded by a tawny facial disk. A conspicuous, narrow, white patch is often visible on the throat. The adult plumage is mottled and varies in color from reddish brown to light or dark grey. The underside usually has fine dark bars on a lighter background. These owls also have large feet that are feathered down to the strong, heavy talons. Immature owls resemble the adults, but their plumage color is generally lighter or more reddish. Their ear tufts are smaller and the white throat patch is not yet distinctive.