Jean-Baptiste Belley (c. 1746 – 1805) was a native of Senegal and former slave from Saint-Domingue in the French West Indies who during the period of the French Revolution became a member of the National Convention and the Council of Five Hundred of France. He was also known as Mars.
Belley was said to have been born on 1 July 1746 or 1747 on the island of Gorée, Senegal, but the dates of his birth and death are uncertain. At the age of two, he was sold to slavers sailing for the French colony of Saint-Domingue. With his savings, he later bought his freedom.
In 1791, the enslaved Africans of Saint-Domingue began the Haitian Revolution, aimed at the overthrow of the colonial regime. As their fellow revolutionaries in France thought the Declaration of the Rights of Man of 1789, they began to see that slavery would need to be abolished.
In 1793, Belley was a Captain of infantry, fought against the colonists of Saint-Domingue and was six times wounded. On 24 September 1793, he was one of three members (deputés) elected to the French National Convention by the northern region of Saint-Domingue, together with Jean-Baptiste Mills, a mulatto, and Louis-Pierre Dufaÿ, a European, thus becoming the first black deputy to take a seat in the Convention. On 3 February 1794, he spoke in a debate in the Convention when it decided unanimously to abolish slavery.
However, the formal abolition of slavery did not disarm the European colonists' supporters, and although he was recognized as a full citizen of the Republic, Belley had to struggle against racist insinuations. He was an active spokesman for people of colour. When Benoît Gouly, a pro-slavery deputy from Mauritius in the Indian Ocean, called for special laws for the colonies, Belley denounced a pressure group of colonists meeting at the Hôtel Massiac in a speech published under the title Le Bout d'oreille des colons, ou le système de l’Hôtel Massiac mis à jour par Gouly. He succeeded for a time in maintaining the Republican principle of equality between people in France and in its colonies, whatever their colour.