Guineafowl (; sometimes called "pet speckled hens" or "original fowl") are birds of the family Numididae in the order Galliformes. They are endemic to Africa and rank among the oldest of the gallinaceous birds. Phylogenetically, they branched off from the core Galliformes after the Cracidae (chachalacas, guans, and curassows) and before the Odontophoridae (New World quail). An Eocene fossil lineage Telecrex has been associated with guineafowl; Telecrex inhabited Mongolia, and may have given rise to the oldest of the true phasianids, such as blood pheasants and eared pheasants, which evolved into high-altitude, montane-adapted species with the rise of the Tibetan Plateau. While modern guineafowl species are endemic to Africa, the helmeted guineafowl has been introduced as a domesticated bird widely elsewhere.
Guineafowl species are found across sub-Saharan Africa, some almost in the entire range, others more localized, such as the plumed guineafowl in west-central Africa and the vulturine guineafowl in north-east Africa. They live in semiopen habitats such as savanna or semideserts, while some, such as the black guineafowl, mainly inhabit forests. Some perch high on treetops.
The helmeted guinea fowl has been introduced in East Africa, South America, the West Indies, the United States, Britain, and India, where it is raised as food or pets.