Reservations in the United States, known as Indian reservations, are sovereign Native American territories that are managed by a tribal government in cooperation with the federal Bureau of Indian Affairs, a branch of the Department of the Interior, located in Washington, DC. There are 334 reservations in the United States today. As of 2008, almost a third of Native Americans in the United States live on reservations, totaling approximately 700,000 individuals. About half of all Native Americans living on reservations are concentrated on the ten largest reservations.

An American Indian reservation is an area of land held and governed by a U.S. federal government-recognized Native American tribal nation, whose government is autonomous, subject to regulations passed by the United States Congress and administered by the United States Bureau of Indian Affairs, and not to the U.S. state government in which it is located. Some of the country's 574 federally recognized tribes govern more than one of the 326 Indian reservations in the United States, while some share reservations, and others have no reservation at all. Historical piecemeal land allocations under the Dawes Act facilitated sales to non–Native Americans, resulting in some reservations becoming severely fragmented, with pieces of tribal and privately held land being treated as separate enclaves. This jumble of private and public real estate creates significant administrative, political, and legal difficulties.