Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are often reared by humans for their meat and eggs, or hunted as game birds.

The order contains about 290 species, inhabiting every continent except Antarctica, and divided into five families: Phasianidae (including chicken, quail, partridges, pheasants, turkeys, peafowl (peacocks) and grouse), Odontophoridae (New World quail), Numididae (guinea fowl), Cracidae (including chachalacas and curassows), and Megapodiidae (incubator birds like malleefowl and brush-turkeys). They adapt to most environments except for innermost deserts and perpetual ice.

Many gallinaceous species are skilled runners and escape predators by running rather than flying. Males of most species are more colorful than the females, with often elaborate courtship behaviors that include strutting, fluffing of tail or head feathers, and vocal sounds. They are mainly nonmigratory. Several species have been domesticated during their long and extensive relationships with humans.

The name galliformes derives from "gallus", Latin for "rooster". Common names are gamefowl or gamebirds, landfowl, gallinaceous birds, or galliforms. Galliforms and waterfowl (order Anseriformes) are collectively called fowl.