This chapter argues that in the Age of Atlantic Revolutions (c. 1770s–1790s) republican conceptions of liberty were put into service of both antislavery and proslavery discourses. Focusing on the American, Dutch, French, and Haitian revolutions, it distinguish three lines of republican reasoning that informed arguments against slavery: the 'extension' of political freedom to enslaved people; the idea that the institution of slavery leads to corruption; and third, the notion of republican liberty as a reward for military courage and sacrifice. It then identifies three ways in which republican conceptions of liberty were widely reconciled with the existence of chattel slavery: only a certain delineated group in society could responsibly enjoy republican liberty; enslaved people were a form of property and therefore not part of a society of free citizens; and finally, the idea that enslaved people who did not resist their slavery, basically acquiesced in their unfree status and were unworthy of republican liberty. Eighteenth-century republican arguments about liberty did not necessarily contradict chattel slavery, but could also form part of the legitimization of slavery. The chapter, then, demonstrates not so much the limits but the versatile employability of the republican discourse of liberty.