By the Law of 20 May 1802, Napoleon Bonaparte reinstates slavery in the French colonies, revoking its abolition in the French Revolution.

The Law of 20 May 1802 was a decree passed by First Consul Napoleon of the French First Republic on 20 May 1802 that reinstated slavery. It decreed the reinstatement and continuation of slavery in French colonies reversing the Law of 4 February 1794, which had abolished the institution in all of France's overseas possessions but was only implemented in Saint-Domingue, Guadeloupe and Cayenne.

Napoleon Bonaparte, later known by his regnal name Napoleon I, was a French general and statesman who rose to prominence during the French Revolution and led a series of military campaigns across Europe during the French Revolutionary and Napoleonic Wars from 1796 to 1815. He led the French Republic as First Consul from 1799 to 1804, then ruled the French Empire as Emperor of the French from 1804 to 1814, and briefly again in 1815. He was King of Italy from 1805 to 1814 and Protector of the Confederation of the Rhine from 1806 to 1813.

Slavery is the ownership of a person as property, especially in regards to their labour. It is an economic phenomenon and its history resides in economic history. Slavery typically involves compulsory work, with the slave's location of work and residence dictated by the party that holds them in bondage. Enslavement is the placement of a person into slavery, and the person is called a slave or an enslaved person.

The French colonial empire consisted of the overseas colonies, protectorates, and mandate territories that came under French rule from the 16th century onward. A distinction is generally made between the "First French colonial empire", that existed until 1814, by which time most of it had been lost or sold, and the "Second French colonial empire", which began with the conquest of Algiers in 1830. On the eve of World War I, France's colonial empire was the second-largest in the world after the British Empire.