Georges Eugène Sorel (/səˈrɛl/; French: [ʒɔʁʒ øʒɛn sɔʁɛl]; 2 November 1847 – 29 August 1922) was a French social thinker, political theorist, historian, and later journalist. He has inspired theories and movements grouped under the name of Sorelianism. His social and political philosophy owed much to his reading of Proudhon, Karl Marx, Giambattista Vico, Henri Bergson (whose lectures at the Collège de France he attended), and later William James. His notion of the power of myth in collective agency inspired socialists, anarchists, Marxists, and fascists. Together with his defense of violence, the power of myth is the contribution for which he is most often remembered.

Politically he evolved from his early liberal-conservative positions towards Marxism, social-democracy, and eventually syndicalism. Between 1909 and 1910 he was marginally involved with Charles Maurras' Action Française, and between 1911 and 1913 he wrote for the politically transversal L'Indépendance, established together with Édouard Berth – one of Sorel's main disciples – and Georges Valois, closer to Maurrassian circles. After a long silence during the war, Sorel came out in favour of Lenin and moved towards Bolshevist positions until his death in 1922.

His legacy in the interwar period embraced both ends of the political spectrum, as many former syndicalists welcomed the emerging fascism. According to historian Zeev Sternhell, Sorel's revision of Marxism broke the necessity of the link between revolution and working class, opening up the possibility of replacing the proletariat with the national community.

Born in Cherbourg as the son of a businessman, he moved to Paris in 1864 to attend the Collège Rollin, before entering the École Polytechnique a year later. In 1869 he became chief engineer with the Department of Public Works. Stationed in Corsica until June 1871, he was subsequently posted to various places in southern France – Albi, Gap, and Draguignan. Between 1876 and 1879 he was in Mostaganem, in colonial Algeria, before moving to Perpignan, where he spent the last years of his career until his retirement in 1892. In 1891, he was awarded the Légion d'honneur. Immediately after retiring, he moved with his partner Marie David to Boulogne-sur-Seine, near Paris, where he stayed until his death in 1922.

Beginning in the second half of the 1880s, he published articles in various fields (hydrology, architecture, philosophy of science, psychophysics, political history, and philosophy) displaying the influence of Aristotle, as well as those of Hippolyte Taine and Ernest Renan. In 1893, he publicly announced his position as a Marxist and a socialist. He moved to working on some of France's first Marxist journals (L’Ère nouvelle and Le Devenir Social) and to participating, on the revisionist side, in the debate launched by Eduard Bernstein. A supporter of Alfred Dreyfus during the affaire, Sorel later was disappointed, much like his friend Charles Péguy, by the political consequences of the trial.

In the beginning of the 20th century, he began arguing for the incompatibility between socialism and parliamentary democracy, moving towards syndicalist positions. Through his writings in Enrico Leone's Il Divenire sociale and Hubert Lagardelle's Mouvement socialiste, he contributed around 1905 to the theoretical elaboration of revolutionary syndicalism. In 1905, his most famous text, Reflections on Violence, began appearing in the Divenire Sociale. It was published in book form in 1908 by Pages Libres, and was followed the same year by Illusions du Progrès.

In the wake of the 1909 defeat of the syndicalist wing of the Confédération Générale du Travail (CGT), Sorel became close for a period in 1909–1910 with Charles Maurras’ Action française, while sharing neither its nationalism nor its political program. This collaboration inspired the founders of the Cercle Proudhon, which brought together revolutionary syndicalists and monarchists. Sorel himself, with Jean Variot, founded a journal in 1911 called L'Indépendance, although disagreements, in part over nationalism, soon ended the project.

Ferociously opposed to the 1914 Union sacrée political truce, Sorel denounced the war and in 1917 praised the Russian Revolution. He wrote for an official Soviet Union publication, Russian Soviet Government Bureau, calling Lenin "the greatest theoretician of socialism since Marx and a statesman whose genius recalls that of Peter the Great." He wrote numerous small pieces for Italian newspapers defending the Bolsheviks. Whereas Sorel's support for Bolshevism is a matter of abundant public record, his much-talked-about interest in the newborn fascist movement is only confirmed by nationalist sources from the interwar period. According to the Maurrassian intellectual Jean Variot, in March 1921, Sorel confided to him that "Mussolini is a man no less extraordinary than Lenin. He, too, is a political genius, of a greater reach than all the statesmen of the day, with the only exception of Lenin…" Some judgments expressed in Sorel's correspondences actually seem to contradict the belief that he was politically sympathetic with fascism. Most notably he wrote to the liberal journalist Mario Missiroli in June 1921, “Things in Italy seem to me to be going very badly [...] The disorder of the fascists, who suppress the state of which [Giolitti] claims to be the intransigent defender, could well bring Italy back to the times of the Middle Ages. It does not seem that the Fascists are more balanced than the Futurists."