Favonius is a Palearctic genus of butterflies in the family Lycaenidae.

- Subgenus Favonius - Favonius cognatus (Staudinger, 1892) north-eastern China and Korea - Favonius cognatus cognatus - Favonius cognatus ackeryi (Fujioka, 1994) - Favonius cognatus latifasciatus (Shirôzu & Hayashi, 1959) Japan - Favonius jezoensis (Matsumura, 1915) Sakhalin, Kuriles, Japan (Hokkaido) - Favonius jezoensis jezoensis - Favonius jezoensis azumajamensis (Kanda, 1994) - Favonius jezoensis daisenensis (Tanaka, 1941) - Favonius jezoensis magnificans Murayama, 1953 - Favonius korshunovi (Dubatolov & Sergeev, 1982) northeastern China, Amur Oblast, Ussuri, Korea - Favonius korshunovi korshunovi - Favonius korshunovi macrocercus (Wakabayashi & Fukuda, 1985) - Favonius korshunovi shinichiroi Fujioka, 2003 - Favonius leechi (Riley, 1939) Szechwan - Favonius orientalis (Murray, 1875) Amur Oblast, Ussuri, Kunashir, north-eastern China, Korea, Japan - Favonius orientalis orientalis - Favonius orientalis shirozui Murayama, 1956 - Favonius orientalis schischkini Kurentzov, 1970 - Favonius taxila (Bremer, 1861) north-eastern and central China, Amur Oblast, Ussuri, Korea, Japan - Favonius ultramarinus (Fixsen, 1887) north-eastern China, Korea and Japan - Favonius ultramarinus ultramarinus Korea - Favonius ultramarinus borealis (Murayama, 1953) Japan - Favonius ultramarinus hayashii (Shirôzu, 1953) Japan - Favonius ultramarinus okumotoi (Koiwaya, 1996) - Favonius ultramarinus suffusa (Leech, 1894) - Favonius unoi Fujioka, 2003 - Favonius watanabei Koiwaya, 2002 Myanmar - Favonius yuasai Shirôzu, 1948 Japan - Favonius yuasai coreensis Myrayama, 1963 South Korea - Subgenus Tasogare Sugiura, 1993 - Favonius saphirinus (Staudinger, 1887) northeastern China, Korea, Japan, Amur Oblast, Ussuri - Incertae sedis - Favonius latimarginata Murayama, 1963 Japan - Favonius leechina Lamas, 2008

- Favonius fujisanus Matsumura, 1910 is now Sibataniozephyrus fujisanus (Matsumura, 1910) - Favonius quercus (Linnaeus, 1758) is now Neozephyrus quercus North Africa, Europe and Asia Minor - Favonius quercus iberica (Staudinger, 1901) Morocco, Algeria, Spain - Favonius quercus interjectus (Verity, 1919) - Favonius quercus longicaudatus (Riley, 1921) Turkey, Azerbaijan, western Iran