Jean Grave (French: [gʁav]; October 16, 1854, Le Breuil-sur-Couze – December 8, 1939, Vienne-en-Val) was an important activist in the French anarchist movement. He was involved with Élisée Reclus' Révolté. Initially a socialist, he became an anarchist after 1880 and a popularizer of Peter Kropotkin's ideas.
In 1892 Grave wrote La société mourante et l'anarchie, prefaced by Octave Mirbeau, for which he was sentenced to two years in prison. Mirbeau, like Élisée Reclus, Paul Adam, and Bernard Lazare had testified on Grave's behalf, but to no avail. The trial only popularised the book, which was rapidly translated into German, Spanish, Portuguese, Italian and Yiddish. An English translation by Voltairine De Cleyre appeared in 1899.
Grave was acquitted in the "Trial of the thirty".
In 1895 he began publishing Les Temps nouveaux, which was influential in literary and artistic circles of the time. Many well-known artists (such as Aristide Delannoy, Maximilien Luce, Paul Signac, Alexandre Steinlen, Théo van Rysselberghe, Camille Pissarro, Kees van Dongen, Charles Angrand, Henri-Edmond Cross, George Willaume, etc.) illustrated and helped to finance the review.
In 1914 Grave joined Kropotkin in England, and incurred the wrath of anti-war anarchists by signing the Manifesto of the Sixteen, which supported the allies during World War I.
Grave also wrote Le Mouvement libertaire sous la IIIe république.