|Number of Species||300|
Milkweed butterflies are a subfamily, Danainae, in the family Nymphalidae, or brush-footed butterflies. They lay their eggs on various milkweeds on which their larvae (caterpillars) feed. Before, this group had been considered a separate family, Danaidae, and the tribes placed here were sometimes considered subfamilies in the Nymphalidae.
There are some 300 species of Danainae worldwide. Most of the Danaini are found in tropical Asia and Africa, while the Ithomiini are diverse in the Neotropics. Tellervini are restricted to Australia and the Oriental region. Four species are found in North America: the Monarch Butterfly (Danaus plexippus); the Queen (Danaus gilippus); the Tropical Milkweed Butterfly (Lycorea cleobaea); and the Soldier Butterfly (or "Tropic Queen"; Danaus eresimus).
The best known member of this family is the Monarch butterfly. The larvae and the butterflies retain poisonous glycosides from their larval host plant, the milkweed, so they become distasteful to potential predators. These milkweed butterflies (Monarch, Queen, Soldier) eat only milkweeds (Asclepias) as larvae. This highly effective defense strategy shields them against almost all predators that soon learn to avoid these species after attempting to eat them.
Another member known especially for its presence in butterfly greenhouses and live butterfly expositions is the Southeast Asian Idea leuconoe.
The fossil milkweed butterfly Archaeolycorea is known from the Oligocene or Miocene Tremembé Formation of Brazil. It often assigned to tribe Danaini, specifically subtribe Euploeina, but this may not be correct. In any case, it provides evidence that the present family originated more than 20-30 million years ago.
Subtribe Danaina Boisduval, 
- Amauris – clerics
- Danaus – monarchs, queens and "tigers"
- Ideopsis – glassy tigers, Southeast Asian tree- and wood-nymphs
- Parantica – "tigers"
- Tiradelphe – Schneider's Surprise
- Tirumala – blue tigers
Subtribus Euploeina Moore, 
- Anetia – anetias and false fritillaries
- Euploea – crows
- Idea – tree nymphs, paper butterflies
- Lycorea – mimic queens
- Protoploea – Magpie Butterfly
The fossil milkweed butterfly Archaeolycorea from the Oligocene or Miocene Tremembé Formation of Brazil is often assigned to this tribe, specifically the Euploeina. Whether this is correct is not entirely certain.
- Tellervo Kirby, 1894
Tribe Ithomiini Godman & Salvin, 1879
- (Subtribe Tithoreina Fox, 1940)
- (Subtribe Melinaeina Clark, 1947)
- (Subtribe Mechanitina Bar, 1878)
- Methona Doubleday 1847 ( = Gelotophye d’Almeida 1940)
- Thyridia Hübner 1816 ( = Xanthocleis Boisduval 1870; = Aprotopus Kirby 1871; = Aprotopos Kirby 1871)
- Scada Kirby 1871 ( = homonym Salacia Hübner 1823; = Heteroscada Schatz 1886)
- Sais Hübner 1816
- Forbestra Fox 1967
- Mechanitis Fabricius 1807 ( = homonym Nereis Hübner 1806; = unavailable name Hymenitis Illiger 1807; = Epimetes Billberg 1820)
- (Subtribe Napeogenina)
- Aremfoxia Réal 1971
- Epityches d'Almeida 1938 ( = homonym Tritonia Geyer 1832)
- Hyalyris Boisduval 1870 ( = Oreogenes Stichel 1899)
- Napeogenes Bates 1862 ( = homonym Ceratonia Boisduval 1870; = Choridis Boisduval 1870)
- Hypothyris Hübner 1821 ( = Mansueta d'Almeida 1922; = Pseudomechanitis Röber 1930; = Garsauritis d'Almeida 1938; = Rhodussa d'Almeida 1939)
- (Subtribe Ithomiina Godman & Salvin, 1879)
- (Subtribe Oleriina)
- (Subtribe Dircennina d'Almeida, 1941)
- Ceratinia Hübner 1816 ( = Calloleria Godman & Salvin 1879; = Epileria Rebel 1902; = Teracinia Röber 1910)
- Callithomia Bates 1862 ( = Cleodis Boisduval 1870; = Epithomia Godman & Salvin 1879; = Corbulis Boisduval 1870; = Leithomia Masters 1973)
- Dircenna Doubleday 1847
- Hyalenna Forbes 1942
- Episcada Godman & Salvin 1879 ( = Ceratiscada Brown & d’Almeida 1970; = Prittwitzia Brown, Mielke & Ebert 1970)
- Haenschia Lamas 2004
- Pteronymia Butler & Druce 1872 ( = Ernicornis Capronnier 1874; = Parapteronymia Kremky 1925; = Talamancana Haber, Brown & Freitas 1994)
- (Subtribe Godyridina)
- Velamysta Haensch 1909
- Godyris Boisduval 1870 ( = Dismenitis Haensch 1903; = Dygoris Fox 1945)
- Veladyris Fox 1945
- Hypoleria Godman & Salvin 1879 ( = homonym Pigritia d’Almeida 1922; = homonym Pigritina Hedicke 1923; = homonym Heringia d’Almeida 1924)
- Brevioleria Lamas 2004
- Mcclungia Fox 1940
- Greta Hemming 1934 ( = homonym Hymenitis Hübner 1819; = Hypomenitis Fox 1945)
- Heterosais Godman & Salvin 1880 ( = Rhadinoptera d'Almeida 1922)
- Pseudoscada Godman & Salvin 1879 ( = Languida d’Almeida 1922)