He was born at Nevers. Until the French Revolution, his main interest was botany. He studied medicine at Paris in 1790, became one of the orators of the club of the Cordeliers, and contributed anonymously to the Revolutions de Paris. As member of the insurrectionary Commune of August 10 1792, he was delegated to visit the prisons, with full power to arrest suspects. He was accused later of having taken part in the massacres of September, but proved that at that time he had been sent by the provisional executive council to Normandy to oversee a requisition. of 60,000 men.
Returning from this mission, he spoke eloquently in favour of the republic. His simple manners, easy speech, and irreproachable private life made him influential, and he was elected president of the Commune, defending the municipality at the bar of the Convention on October 31 1792. Re-elected in the municipal elections of December 2 1792, he was soon given the functions of procurator of the Commune, and contributed with success to the enrolments of volunteers by his appeals to the populace. Chaumette was one of the ringleaders in the attacks of May 31 and of June 2 1793 on the Girondists, toward whom he showed himself relentless.
He demanded the formation of a revolutionary army, and preached the extermination of all traitors. He promoted the worship of Reason, and on November 10 1793 he presented the "goddess" to the Convention in the guise of an actress. On 23 November, he obtained a decree closing all the churches of Paris, and placing the priests under strict surveillance; but two days later he obtained from the Commune the free exercise of worship. He wished to save the Hébertists by a new insurrection and struggled against Robespierre; but a revolutionary decree promulgated by the Commune on his demand was overthrown by the Convention. Robespierre had him accused with the Hébertists. Chaumette was arrested, imprisoned in the Luxembourg, condemned by the Revolutionary tribunal and executed on April 13, 1794.
Chaumette was an ardent social reformer; he secured the abolition of corporal punishment in schools, the suppression of lotteries, of houses of ill-fame and of obscene literature; he instituted reforms in the hospitals, and insisted on the honours of public burial for the poor. Chaumette left some printed speeches and fragments, and memoirs published in the Amateur d'autographes. His memoirs on August 10 were published by FA Aulard, preceded by a biographical study.