The Blackfoot Confederacy or Niitsítapi (meaning "original people"; c.f.

Ojibwe: Anishinaabeg and Quinnipiac: Eansketambawg) is the collective name of three First Nations in Alberta and one Native American tribe in Montana.The Blackfoot Confederacy consists of the North Peigan (Aapátohsipikáni), the Piegan Blackfeet or South Piegan (Aamsskáápipikani), the Kainai Nation (Káínaa: "Blood"), and the Siksika Nation ("Blackfoot") or more correctly Siksikáwa ("Blackfoot people").

The South Peigan are located in Montana, and the other three are located in Alberta.

Together they call themselves the Niitsítapi (the "Original People").

These groups shared a common dialect of the Algonquin language (also seen as "Algonkian") as well as a common culture.

They also had treaties of mutual defense, and members of the groups freely intermarried.