The Tsuu T’ina (also Sarsi or Sarcee) are a nation of the First Nations of Canada. Their nation is located adjacent to the southwest city limits of Calgary, Alberta.

The Tsuu T’ina language belongs to the Athabaskan language family, which include the Navajo and Apache of the south, and the Chippewa and Dene of the north. Tsuu T’ina means "a great number of people".

They are also known by the names of the Sarcee or Sarsi. Sarcee is believed to have been derived from a Blackfoot word meaning boldness and hardiness.