The Tohono Oüodham Nation Indian Reservation, is an Indian reservation of the Tohono Oüodham Nation in Arizona, United States. The reservation had a 2020 census population of 9,561. It has an area of , 97.48 percent of the Tohono Oüodham Nation's total area. The reservation encompasses parts of central Pima, southwestern Pinal, and southeastern Maricopa Counties.
The land is also the site of the Quinlan and Baboquivari Mountains, which include Kitt Peak, and the Kitt Peak National Observatory and telescopes, as well as Baboquivari Peak. These astronomical sites are under lease from the Tohono Oüodham Nation. The lease was approved by the council in the 1950s, for a one-time payment of US$25,000 plus $10 per acre per year.
When Spaniards first encountered the tribe in 1694, they made note of one of the tribe's inhabited villages called Batki, a site that was abandoned around 1850. Batki was in what is now the Sells District of the Tohono O'odham Nation.
The telephone area code for the Tohono Oüodham Reservation is 520.