Rallus is a genus of wetland birds of the rail family. Sometimes, the genera Lewinia and Gallirallus are included in it. Six of the species are found in the Americas, and the three species found in Eurasia, Africa and Madagascar are very closely related to each other, suggesting they are descended from a single invasion of a New World ancestor.

Rails are a large, cosmopolitan family of small- to medium-sized terrestrial and/or semi-amphibious birds. The family exhibits considerable diversity in its forms, and includes such ubiquitous species as the crakes, coots, and gallinule; other rail species are extremely rare or endangered. Many are associated with wetland habitats, some being semi-aquatic like waterfowl, but many more are wading birds or shorebirds. The ideal rail habitats are marsh areas, including rice paddies, and flooded fields or open forest. They are especially fond of dense vegetation for nesting. The rail family is found in every terrestrial habitat with the exception of dry desert, polar or freezing regions, and alpine areas. Members of Rallidae occur on every continent except Antarctica. Numerous unique island species are known.