Taxonomy and naming
The red-billed quelea was one of the many
birds described originally by
Linnaeus in the landmark 1758
10th edition of his
Systema Naturae. Classifying it in the
Emberiza, he gave it the
binomial name of Emberiza quelea.
 He incorrectly mentioned that it originated in India, probably because ships from the East Indies picked up birds when visiting the African coast during their return voyage to Europe. It is likely that he had seen a draft of Ornithologia, sive Synopsis methodica sistens avium divisionem in ordines, sectiones, genera, species, ipsarumque varietates, a book written by
Mathurin Jacques Brisson that was to be published in 1760, and which contained a black and white drawing of the species. The erroneous
type locality of India was corrected to Africa in the 12th edition of
Systema Naturae of 1766, and Brisson was
cited. Brisson mentions that the bird originates from Senegal, where it had been collected by
Michel Adanson during his 1748-1752 expedition.
 He called the bird Moineau a bec rouge du Senegal in French and Passer senegalensis erythrorynchos in Latin, both meaning "red-billed Senegalese sparrow".
 Also in 1766,
George Edwards illustrated the species in colour, based on a live male specimen owned by a Mrs Clayton in Surrey. He called it the "Brazilian sparrow", despite being unsure whether it came from
 In 1850,
Ludwig Reichenbach thought the species was not a
true bunting, but rather a weaver, and created the genus name Quelea, as well as the
new combination Q. quelea.
 The white-faced
morph was described as a separate species, Q. russii.
Three subspecies are recognised. In the field, these are distinguished by differences in male breeding plumage.
nominate subspecies, Quelea quelea quelea, is native to west and central Africa, where it has been recorded from Mauritania, western and northern Senegal, Gambia, central Mali, Burkina Faso, southwestern and southern Niger, northern Nigeria, Cameroon, south-central Chad and northern Central African Republic.
- Loxia lathamii was described by
Andrew Smith in 1836,
 but later assigned to Q. quelea as its subspecies lathamii. It ranges across central and southern Africa, where it has been recorded from southwestern Gabon, southern Congo, Angola (except the northeast and arid coastal southwest), southern Democratic Republic of Congo and the mouth of the Congo River, Zambia, Malawi and western Mozambique across to Namibia (except the coastal desert) and central, southern and eastern South Africa.
- Ploceus aethiopicus was described by
Carl Jakob Sundevall in 1850, but later assigned to Q. quelea as its subspecies aethiopica. It is found in eastern Africa where it occurs in southern Sudan, eastern South Sudan, Ethiopia and Eritrea south to the northeastern parts of the Democratic Republic of Congo, Uganda, Kenya, central and eastern Tanzania and northwestern and southern Somalia.
Formerly, two other subspecies have been described. Q. quelea spoliator was described by
Phillip Clancey in 1960 on the basis of more greyish nonbreeding plumage of populations of wetter habitats of northeastern South Africa, Swaziland and southern Mozambique. However, further analysis indicated no clear distinction in plumage between it and Q. quelea lathamii, with no evidence of genetic isolation.
 Hence it is not recognised as distinct. Q. quelea intermedia, described by
Anton Reichenow in 1886 from east Africa, is regarded a
synonym of subspecies aethiopica.
Etymology and vernacular names
Linnaeus himself did not explain the name quelea.
 Quelea quelea is locally called kwelea domo-jekundu in
Swahili, enzunge in
Kwangali, chimokoto in
Shona, inyonyane in
Siswati, thaha in
Sesotho and ndzheyana in the
 M.W. Jeffreys suggested that the term came from medieval Latin qualea, meaning "quail", linking the prodigious numbers of queleas to the hordes of quail that fed the Israelites during
the Exodus from Egypt.
The subspecies lathamii is probably named in honor of the ornithologist
 The name of the subspecies aethiopica refers to Ethiopia,
 and its
type was collected in the neighbouring
Sennar province in today's Sudan.
"Red-billed quelea" has been designated the official name by the
International Ornithological Committee (IOC).
 Other names in English include black-faced dioch, cardinal, common dioch, Latham's weaver-bird, pink-billed weaver, quelea finch, quelea weaver, red-billed dioch, red-billed weaver, Russ' weaver, South-African dioch, Sudan dioch and Uganda dioch.
Based on recent
DNA analysis, the red-billed quelea is the
sister group of a clade that contains both other remaining species of the genus
Quelea, namely the
cardinal quelea (Q. cardinalis) and the
red-headed quelea (Q. erythrops). The genus belongs to the group of true weavers (subfamily Ploceinae), and is most closely related to the fodies (
Foudia), a genus of six or seven species that occur on the
islands of the western Indian Ocean. These two genera are in turn the sister clade to the Asian species of the genus
Ploceus. The following tree represents current insight of the relationships between the species of Quelea, and their closest relatives.
Interbreeding between red-billed and red-headed queleas has been observed in captivity.