The Blackfoot language, also called Siksiká, often anglicised as Siksika, is an Algonquian language spoken by the Blackfoot or Niitsitapi people, who currently live in the northwestern plains of North America. There are four dialects, three of which are spoken in Alberta, Canada, and one of which is spoken in the United States: Siksiká (Blackfoot), to the southeast of Calgary, Alberta; Kainai, spoken in Alberta between Cardston and Lethbridge; Aapátohsipikani, to the west of Fort MacLeod which is Brocket (Piikani) and Aamsskáápipikani, in northwestern Montana. The name Blackfoot probably comes from the blackened soles of the leather shoes that the people wore.

The Siksika Nation is a First Nation in southern Alberta, Canada. The name Siksiká comes from the Blackfoot words sik (black) and iká (foot), with a connector s between the two words. The plural form of Siksiká is Siksikáwa. The Siksikáwa are the northernmost of the Niitsítapi, all of whom speak dialects of Blackfoot, an Algonquian language.