The Yuma War was the name given to a series of United States military operations conducted in southern California and what is today southwestern Arizona from 1850 to 1853. The Quechan were the primary opponent of the United States Army, though engagements were fought between the Americans and other native groups in the region.

The Quechan, or Yuma, are a Native American tribe who live on the Fort Yuma Indian Reservation on the lower Colorado River in Arizona and California just north of the Mexican border. Despite their name, they are not related to the Quechua people of the Andes. Members are enrolled into the Quechan Tribe of the Fort Yuma Indian Reservation. The federally recognized Quechan tribe's main office is located in Winterhaven, California. Its operations and the majority of its reservation land are located in California, United States.