Marcus Mosiah Garvey Jr. (17 August 1887 – 10 June 1940) was a Jamaican political activist, publisher, journalist, entrepreneur, and orator. He was the founder and first President-General of the Universal Negro Improvement Association and African Communities League (UNIA-ACL, commonly known as UNIA), through which he declared himself Provisional President of Africa. Ideologically a black nationalist and Pan-Africanist, his ideas came to be known as Garveyism.

Garvey was born into a moderately prosperous Afro-Jamaican family in Saint Ann's Bay and he was apprenticed into the print trade as a teenager. Working in Kingston, he got involved in trade unionism before he lived briefly in Costa Rica, Panama, and England. After he returned to Jamaica, he founded the UNIA in 1914. In 1916, he moved to the United States and established a UNIA branch in New York City's Harlem district. Emphasising unity between Africans and the African diaspora, he campaigned for an end to European colonial rule across Africa and advocated the political unification of the continent. He envisioned a unified Africa as a one-party state, governed by himself, that would enact laws to ensure black racial purity. Although he never visited the continent, he was committed to the Back-to-Africa movement, arguing that part of the diaspora should migrate there. Garveyist ideas became increasingly popular and the UNIA grew in membership. However, his black separatist views—and his relationship with white racists like the Ku Klux Klan (KKK) in the interest of advancing their shared goal of racial separatism—caused a division between Garvey and other prominent African-American civil rights activists such as W. E. B. Du Bois who promoted racial integration.

Believing that black people needed to be financially independent from white-dominated societies, Garvey launched various businesses in the U.S., including the Negro Factories Corporation and Negro World newspaper. In 1919, he became President of the Black Star Line shipping and passenger company, designed to forge a link between North America and Africa and facilitate African-American migration to Liberia. In 1923 Garvey was convicted of mail fraud for selling the company's stock, and he was imprisoned in the United States Penitentiary, Atlanta for nearly two years. Many commentators have argued that the trial was politically motivated; Garvey blamed Jewish people, claiming that they were prejudiced against him because of his links to the KKK. After his sentence was commuted by U.S. president Calvin Coolidge, he was deported to Jamaica in 1927. Settling in Kingston with his wife Amy Jacques, Garvey established the People's Political Party in 1929, briefly serving as a city councillor. With the UNIA in increasing financial difficulty, he relocated to London in 1935, where his anti-socialist stance distanced him from many of the city's black activists. He died there in 1940, and in 1964, his body was returned to Jamaica for reburial in Kingston's National Heroes Park.

Garvey was a controversial figure. Some in the African diasporic community regarded him as a pretentious demagogue and they were highly critical of his collaboration with white supremacists, his violent rhetoric, and his prejudice against mixed-race people and Jews. Nevertheless, he received praise for encouraging a sense of pride and self-worth among Africans and the African diaspora amid widespread poverty, discrimination, and colonialism. In Jamaica he is widely regarded as a national hero. His ideas exerted a considerable influence on such movements as Rastafari, the Nation of Islam, and the Black Power Movement.