- The U.S. Census Bureau reported that 18,403 people of all races lived on the Nez Perce Reservation in 2020, compared to 18,437 in 2010, and 17,806 in 1980.
- The population on the Nez Perce Reservation decreased by 0.2 percent from 2010 to 2020.
Please note that ORTL stands for Off-Reservation Trust Land.