Surrealist automatism is spontaneous writing, drawing, or the like practiced without conscious aesthetic or moral self-censorship.

It is to be distinguished from mediumistic automatism, by which it was inspired: ghosts, spirits or the like are not purported to be the source of its automatic messages.

"Pure psychic automatism" was how André Breton, surrealism's founder, defined surrealism.

In 1919 Breton and Philippe Soupault wrote the first automatic book, Les Champs Magnetiques.

"The Automatic Message" was one of Breton's most significant theoretical works about automatism.

Some Romanian surrealists invented a number of surrealist techniques (such as cubomania, entopic graphomania, and the movement of liquid down a vertical surface) that purported to take automatism to an absurd point; the name "surautomatism" implies that the methods "go beyond" automatism but this position is controversial.

In the 1940s and 1950s there were a group of Canadians called Les Automatistes, who pursued creative work (chiefly painting) based on surrealist principles.

Some surrealists write automatic mathematics or equations.