COINTELPRO (Counter Intelligence Program/1956–1971) was a series of covert and illegal projects actively conducted by the United States Federal Bureau of Investigation (FBI) aimed at surveilling, infiltrating, discrediting, and disrupting domestic American political organizations. FBI records show COINTELPRO resources targeted groups and individuals the FBI deemed subversive, including feminist organizations, the Communist Party USA, anti–Vietnam War organizers, activists of the civil rights movement and Black Power movement (e.g. Martin Luther King Jr., the Nation of Islam, and the Black Panther Party), environmentalist and animal rights organizations, the American Indian Movement (AIM), Chicano and Mexican-American groups like the Brown Berets and the United Farm Workers, independence movements (including Puerto Rican independence groups such as the Young Lords and the Puerto Rican Socialist Party), a variety of organizations that were part of the broader New Left, and far-right groups such as the Ku Klux Klan and the National States' Rights Party.

In 1971 in San Diego, the FBI financed, armed, and controlled an extreme right-wing group of former members of the Minutemen anti-communist paramilitary organization, transforming it into a group called the Secret Army Organization that targeted groups, activists, and leaders involved in the Anti-War Movement, using both intimidation and violent acts.

The FBI has used covert operations against domestic political groups since its inception; however, covert operations under the official COINTELPRO label took place between 1956 and 1971. Many of the tactics used in COINTELPRO are alleged to have seen continued use including; discrediting targets through psychological warfare; smearing individuals and groups using forged documents and by planting false reports in the media; harassment; wrongful imprisonment; illegal violence; and assassination. According to a Senate report, the FBI's motivation was "protecting national security, preventing violence, and maintaining the existing social and political order".

Beginning in 1969, leaders of the Black Panther Party were targeted by the COINTELPRO and "neutralized" by being assassinated, imprisoned, publicly humiliated or falsely charged with crimes. Some of the Black Panthers targeted include Fred Hampton, Mark Clark, Zayd Shakur, Geronimo Pratt, Mumia Abu-Jamal, and Marshall Conway. Common tactics used by COINTELPRO were perjury, witness harassment, witness intimidation, and withholding of exculpatory evidence.

FBI Director J. Edgar Hoover issued directives governing COINTELPRO, ordering FBI agents to "expose, disrupt, misdirect, discredit, or otherwise neutralize" the activities of these movements and especially their leaders. Under Hoover, the agent in charge of COINTELPRO was William C. Sullivan. Attorney General Robert F. Kennedy personally authorized some of the programs, giving written approval for limited wiretapping of Martin Luther King's phones "on a trial basis, for a month or so."Hoover extended the clearance so his men were "unshackled" to look for evidence in any areas of King's life they deemed worthy.