It is found in arctic and subarctic regions of North America, Europe, and Asia during the breeding season, and migrates south for the winter.

[3] A broad brown chest-band is present in most plumages and a square dark carpal patch contrasting with the white under-wing is an easily identifiable characteristic in light morph individuals.

[3] A wide variety of plumage patterns are exhibited in light vs. dark morphs, males vs. females, and adults vs. juveniles.

Its scientific name reflects this feature; the genus name Buteo is the Latin name of the common buzzard, and lagopus, is derived from Ancient Greek lago (λαγως), meaning "hare", and pous (πους), "foot".

[3] The common buzzard can be similar-looking, with a similar long-tailed shape and can be notoriously variable in plumage; rough-legged is longer-winged and more eagle-like in appearance.

The ferruginous hawk is larger, with a bigger, more prominent bill and has a whitish comma at the wrist and all-pale tail.

The rough-legged buzzard is a member of the genus Buteo, a group of moderately large raptors exhibiting broad wings, short tails and wide robust bodies.

[3] Four subspecies of Buteo lagopus are accepted:[2] The rough-legged buzzard breeds in tundra and taiga habitats of North America and Eurasia between the latitudes of 61° (locally south to 48° in Newfoundland and 58° N in southern Norway) and 76° N. Those occurring in North America migrate to southern Canada and into the central United States for the winter, while Eurasian birds migrate to central Europe and Asia, with small numbers west to eastern parts of Great Britain; most winter between latitudes of 43° and 58° N. It is the only member of its diverse genus found in all three of the northern continents, having a complete circumpolar distribution.

During the winter months, from October to April, preferred habitats include marshes, moorland, prairies and agricultural regions where rodent prey is most abundant.

[3][12][21] Some evidence suggests that they may be able to see vole scent marks which are only visible in the ultraviolet range, allowing them to cue in on prey.

[24] The rough-legged buzzard will also supplement its diet with mice, rats, gerbils, pikas, shrews, squirrels of the genera Spermophilus and Tamias,[25] and insects.

Most avian prey species are small passerines such as snow bunting (Plectrophenax nivalis), Lapland longspur (Calcarius lapponicus), American tree sparrow (Spizelloides arborea) and thrushes (Turdus spp.).

[12] This avian predator hunts opportunistically, occasionally supplementing its diet with carrion but focusing primarily on the most locally abundant small vertebrates.

After the breeding season, they make long-distance prospecting flights, look for a suitable habitat with high rodent numbers, and return to that place the following year.

The threats faced by young rough-legs can include starvation when prey is not numerous, freezing when Northern conditions are particularly harsh during brooding, destruction by humans, and predation by various animals.

Death of flying immatures and adults are often the result of human activity, including collisions with power lines, buildings, and vehicles, incidental ingestion of poison or lead from prey, or illegal hunting and trapping.

[32] Avian scavengers, especially groups of common ravens, will also readily prey on eggs and nestlings, as will skuas (Stercorarius spp.).

If weather then rapidly changes to the thunderstorm (which is common in the Arctic) nestlings could die without parent protection in a short time in 3–5 m from the nest.

It is described as a downward slurring whistle, sounding like kiu wiyuk or a lengthy descending kee-eer similar to that of the red-tailed hawk.