Joseph Déjacque (December 27, 1821, Paris – 1864, Paris) was a French anarcho-communist poet and writer. He sought to abolish "personal property, property in land, buildings, workshops, shops, property in anything that is an instrument of work, production or consumption."[1]

Déjacque was the first to employ the term libertarian (French: libertaire) in a political sense, in a letter written in 1857 criticizing Proudhon for an alleged attack on feminism and his support of individual ownership of the product of labor, and of a market economy, saying: "it is not the product of his or her labor that the worker has a right to, but to the satisfaction of his or her needs, whatever may be their nature."[2] "Libertarian" was from this point forward used by many on the hard left in Europe as a synonym for anti-state socialism; and in particular social anarchism.