Joseph Arthur de Gobineau (French: [ɡɔbino]; 14 July 1816 – 13 October 1882) was a French aristocrat who is best known for helping to legitimise racism by the use of scientific racist theory and "racial demography", and for developing the theory of the Aryan master race. Known to his contemporaries as a novelist, diplomat and travel writer, he was an elitist who, in the immediate aftermath of the Revolutions of 1848, wrote An Essay on the Inequality of the Human Races. In it he argued aristocrats were superior to commoners, and that aristocrats possessed more Aryan genetic traits because of less interbreeding with inferior races.

Gobineau's writings were quickly praised by white supremacist, pro-slavery Americans like Josiah C. Nott and Henry Hotze, who translated his book into English. They omitted around 1,000 pages of the original book, including those parts that negatively described Americans as a racially mixed population. Inspiring a social movement in Germany named Gobinism, his works were also influential on prominent antisemites like Richard Wagner, Wagner's son-in-law Houston Stewart Chamberlain, the Romanian politician Professor A. C. Cuza, and leaders of the Nazi Party, who later edited and re-published his work.