French social psychologist best known for his study of the psychological characteristics of crowds.

After receiving a doctorate of medicine, Le Bon traveled in Europe, North Africa, and Asia and wrote several books on anthropology and archaeology. His interests later shifted to natural science and social psychology. In Les Lois psychologiques de l'évolution des peuples (1894; The Psychology of Peoples) he developed a view that history is the product of racial or national character, with emotion, not intelligence, the dominant force in social evolution. He attributed true progress to the work of an intellectual elite.

Le Bon believed that modern life was increasingly characterized by crowd assemblages. In La psychologie des foules (1895; The Crowd), his most popular work, he argued that the conscious personality of the individual in a crowd is submerged and that the collective (collective behaviour) crowd mind dominates; crowd behaviour is unanimous, emotional, and intellectually weak.