The Siouan languages are a Native American language family of North America. Some linguists group the Siouan languages together with the Caddoan and Iroquoian languages in a Macro-Siouan language family.

Siouan languages

• Catawba language
• Siouan proper languages
  • Central Siouan languages
    • Mandan language
    • Iowa-Oto language
    • Assiniboine language
    • Dakota language
    • Lakota language
    • Stoney language (Nakota or Nakoda)
    • Kansa language
    • Omaha-Ponca language
    • Osage language
    • Quapaw language
    • Winnebago language (Hocák language)
  • Missouri Valley Siouan languages
    • Crow language (Absaroka)
    • Hidatsa language
  • Southeastern Siouan languages
    • Biloxi language
    • Oto language
    • Tutelo language