The Navajo Nation (Naabeehó Bináhásdzo) is a Native American territory covering about 17,544,500 acres (71,000 km2; 27,413 sq mi), occupying portions of northeastern Arizona, southeastern Utah, and northwestern New Mexico in the United States. This is the largest land area retained by a Native American tribe, with a population of roughly 340,000.

The original territory has been expanded several times since the 1800s. In 2016 under the Tribal Nations Buy-Back Program, some 149,524 acres (605.10 km2; 233.63 sq mi) of land were returned by the Department of Interior to the Navajo Nation for tribal communal use. The program is intended to help restore the land bases of reservations.