The Brush Rabbit (Sylvilagus bachmani), or Western Brush Rabbit, is a species of cottontail rabbit found in western coastal regions of North America, from the Columbia River in Oregon to the southern tip of the Baja California peninsula. Its range extends as far east as the eastern sides of the Sierra Nevada and Cascade mountain ranges.

The Brush Rabbit is smaller than many of the cottontails, and unlike most of them, the underside of its tail is grey rather than white (which may be why its common name does not include the word "cottontail").

Large numbers of geographically defined subspecies have been proposed, including in Oregon, ubericolor; in California, cinerascens, mariposae, riparius, tehamae and trowbridgii; and in Baja California, cerrosensis, exiguus, howelli, peninsularis and rosaphagus. Subspecies bachmani, macrorhinus and virgulti are less geographically restricted. Sylvilagus bachmani riparius, the Riparian Brush Rabbit, is highly endangered; formerly numerous along the San Joaquin River and Stanislaus River , it is now reduced to a population of a few hundred in the Caswell Memorial State Park .

Unlike many rabbits, the Brush Rabbit rarely uses burrows. It lives in brush or grassland, and forms a network of runways through the vegetation. It feeds mainly on grasses and forbs, especially green clover, though it will also take berries and browse from bushes. Its predators include mountain lions, coyotes, and various hawks and snakes; its escape strategies include remaining immobile, and zig-zag running. The young are born above ground, but are altricial. Up to 5 litters a year may be born, but three is more usual.