The Nation of Islam (NOI) is a religious and political organization founded in the United States by Wallace Fard Muhammad in 1930. A black nationalist organization, the NOI focuses its attention on the African diaspora, especially on African Americans. While it identifies itself as promoting a form of Islam, its beliefs differ considerably from mainstream Islamic traditions. Scholars of religion characterize it as a new religious movement. It operates as a centralized and hierarchical organization.

The Nation teaches that there has been a succession of mortal gods, each a black man named Allah, of whom Fard Muhammad is the most recent. It claims that the first Allah created the earliest humans, the Arabic-speaking, dark-skinned Tribe of Shabazz, whose members possessed inner divinity and from whom all people of color are descended. It maintains that a scientist named Yakub then created the white race. The whites lacked inner divinity, and were intrinsically violent; they overthrew the Tribe of Shabazz and achieved global dominance. Setting itself against the white-dominated society of the United States, the NOI campaigns for the creation of an independent African American nation-state, and calls for African Americans to be economically self-sufficient and separatist. A millenarian tradition, it maintains that Fard Muhammad will soon return aboard a spaceship, the "Mother Plane" or "Mother Ship," to wipe out the white race and establish a utopia. Members worship in buildings called mosques or temples. Practitioners are expected to live disciplined lives, adhering to strict dress codes, specific dietary requirements, and patriarchal gender roles.

Wallace Fard Muhammad established the Nation of Islam in Detroit. He drew on various sources, including Noble Drew Ali's Moorish Science Temple of America, black nationalist trends like Garveyism, and black-oriented forms of Freemasonry. After Fard Muhammad disappeared in 1934, the leadership of the NOI was assumed by Elijah Muhammad. He expanded the NOI's teachings and declared Fard Muhammad to be the latest Allah. Attracting growing attention in the late 1950s and 1960s, the NOI's influence expanded through high-profile members such as the black nationalist activist Malcolm X and the boxer Muhammad Ali. Deeming it a threat to domestic security, the Federal Bureau of Investigation worked to undermine the group. Following Elijah Muhammad's death in 1975, his son Warith Deen Mohammed took over the organization, moving it towards Sunni Islam and renaming it the World Community of Islam in the West. Members seeking to retain Elijah Muhammad's teachings re-established the Nation of Islam under Louis Farrakhan's leadership in 1977. Farrakhan has continued to develop the NOI's beliefs, for instance by drawing connections with Dianetics, and expanding its economic and agricultural operations.

Based in the United States, the Nation of Islam has also established a presence abroad, with membership open only to people of color. In 2007, it was estimated to have 50,000 members. The Nation has proven to be particularly successful at converting prisoners. The Southern Poverty Law Center and the Anti-Defamation League have accused it of being a black supremacist hate group that promotes racial prejudice towards white people, anti-semitism, and anti-LGBT rhetoric. Muslim critics accuse it of promoting teachings that are not authentically Islamic.