Peromyscus

See text.

The genus Peromyscus contains the animal species commonly referred to as deer mice. This is a genus of New World mouse only distantly related to the common house mouse and laboratory mouse, Mus musculus. Although superficially resembling Mus musculus, Peromyscus have relatively larger eyes, and also often two-tone coloring, with darker colors over the dorsum (back), and white abdominal and limb hair-coloring. In reference to the coloring, the word Peromyscus comes from Greek words meaning "booted mouse".

They are also accomplished jumpers and runners by comparison to house mice, and their common name of "deer mouse" (coined 1833) is in reference to this agility.

The most common species of deer mice in the continental United States are two closely related species, P. maniculatus, and P. leucopus. In the United States, Peromyscus is the most populous mammalian genus overall, and has become notorious in the western United States as a carrier of the hantavirus.

There is a different mammal by the name of "Mouse Deer", a relatively primitive ungulate of minuscule size.