The drownings at Nantes were a series of mass executions by drowning during the Reign of Terror in Nantes, France, that occurred between November 1793 and February 1794. During this period, anyone arrested and jailed for not consistently supporting the Revolution, or suspected of being a royalist sympathizer, especially Catholic priests and nuns, was cast into the river Loire and drowned on the orders of Jean-Baptiste Carrier, the representative-on-mission in Nantes. Before the drownings ceased, as many as four thousand or more people, including innocent families with women and children, died in what Carrier himself called "the national bathtub".

The Reign of Terror was a period of the French Revolution when, following the creation of the First Republic, a series of massacres and numerous public executions took place in response to revolutionary fervour, anticlerical sentiment, and accusations of treason by the Committee of Public Safety. While terror was never formally instituted as a legal policy by the Convention, it was more often employed as a concept.