The wild asses (Asinus) are a subgenus of single toed grazing ungulates. Its species are:
- African wild ass Equus africanus
- Atlas wild ass Equus africanus atlanticus
- Donkey Equus africanus asinus
- Nubian wild ass Equus africanus africanus (likely ancestor of the domestic donkey)
- Somali wild ass Equus africanus somaliensis
- Kiang (Tibetan wild ass, khyang, or gorkhar) Equus kiang
- Eastern kiang Equus kiang holdereri
- Northern kiang Equus kiang chu
- Southern kiang Equus kiang polyodon
- Western kiang Equus kiang kiang
- Onager (Asiatic wild ass) Equus hemionus
- European wild ass (hydruntine), Equus hydruntinus or Equus hemionus hydruntinus
- Indian wild ass (khur), Equus hemionus khur
- Mongolian wild ass (khulan), Equus hemionus hemionus
- Persian onager (gur), Equus hemionus onager
- Syrian wild ass (hemippe), Equus hemionus hemippus (extinct)
- Turkmenian kulan (kulan), Equus hemionus kulan