Abolitionism succeeded thanks to the struggles of many movements, some genuinely global, others national or local but interconnected at a global level. This article takes a pluralist approach to global abolitionism. Since the late 17th century, the membership, objectives, and strategies of different abolitionist movements have been varied, but they shared the same objective: to impose their understanding of slavery as an aberration that ought to be de-legalized and eventually prohibited worldwide. This article periodizes global abolitionism in three main stages characterized, successively, by the primacy of egalitarianism, imperialism, and internationalism. By the mid-20th century, pro-slavery ideologies were obsolete in Euro-America and had disappeared from official policy globally. They survived in circumscribed contexts in which anti-slavery activists are struggling against the lingering vitality of pro-slavery ideas in the 21st century.