Lone Wolf v. Hitchcock (1903) was a U.S. Supreme Court decision that abrogated Native American treaty rights and underscored congressional supremacy (called plenary power) over Indian affairs. Plaintiffs Lone Wolf and several other Indians had sued the defendant, Interior Secretary Ethan Allen Hitchcock, to block allotment of the Kiowa-Comanche- Apache Reservation in southwestern Oklahoma. Kiowa claims, including the condition of article 12 of the Medicine Lodge Treaty (1867) forbidding cession of Indian land unless approved by three-fourths of the tribe's male members, were sidestepped in the Court's opinion. In 1900 Congress had approved a modified 1892 allotment agreement that did not contain sufficient signatures, even with forgeries, and Lone Wolf and his supporters sought judicial relief. Their case had been rejected in federal court in Washington dc and in the District of Columbia Court of Appeals.

The decision was the culmination of a century-long congressional assault on Indian land and treaty rights. The Court held that congressional guardianship over Indian reservation property could not be limited by an Indian treaty and cited its own decree in Cherokee Nation v. Georgia (1831) that Congress possessed complete administrative power over Indian tribal property. Referring to the earlier decision in United States v. Kagama (1886), the justices upheld congressional supremacy over the nation's "Indian wards," called paternalism, ruling that congressional plenary authority over Indian relations was not subject to judicial oversight or review, since such congressional power was political.

The Court's decision had reverberations far from Lone Wolf's own reservation, which was quickly allotted. The unallotted "surplus" was opened to a tide of non-Indian settlers, who rapidly engulfed tribal lands. Although Indian land division had been under way before the opinion, the judicial pronouncement spurred a frenzy of allotment. Indian land loss increased, not least on reservations on the Northern Great Plains. Indian Office abuses of Indian land, resources, and rights increased in the ensuing years. Indian nations sank deeper into the mire of wardship, subject to virtually unlimited federal authority. The plenary doctrine of Lone Wolf dominated federal Indian law and Indian policy for more than half a century. The decree set back the efforts of humanitarian reformers, who advocated modifications in Indian policy. At the same time in the nation's history, the United States acquired its first overseas possessions, following the conclusion of the Spanish-American War. U.S. authorities viewed local island independence in the same light as that of continental Native American tribal independence, as the attitudes visible in the Lone Wolf litigation were applied narrowly to the new possessions.

Although officially repudiated in the judicial system since 1980 (United States v. Sioux Nation of Indians), the doctrine periodically has been resurrected in defense of denying Indian rights, such as in Indian religious freedom rights and those dealing with sacred sites. The Indian trust funds scandal at the end of the 1990s, involving Bureau of Indian Affairs mismanagement of Indian trust money, was also a long-postponed but direct outgrowth of the Lone Wolf decision and its attendant bureaucratic mind-set.