Earning international acclaim, his work has been interpreted as Surrealism, a sandbox for the subconscious mind, a re-creation of the childlike, and a manifestation of Catalan pride. In numerous interviews dating from the 1930s onwards, Miró expressed contempt for conventional painting methods as a way of supporting bourgeois society, and famously declared an "assassination of painting" in favour of upsetting the visual elements of established painting.

Born to the families of a goldsmith and watchmaker, the young Miró was drawn towards the arts community that was gathering in Montparnasse and in 1920 moved to Paris. There, under the influence of the poets and writers, he developed his unique style: organic forms and flattened picture planes drawn with a sharp line. Generally thought of as a Surrealist because of his interest in automatism and the use of sexual symbols (for example, ovoids with wavy lines emanating from them), Miró's style was influenced in varying degrees by Surrealism and Dada, yet he rejected membership to any artistic movement in the interwar European years. André Breton, the founder of Surrealism, described him as "the most Surrealist of us all." Miró confessed to creating one of his most famous works, Harlequin's Carnival, under similar circumstances:

Joan Miró was originally part of the Generation of '27, a collective made up of Spanish poets, writers, painters and film makers that included Luis Buñuel, Miguel Hernández, José María Hinojosa and García Lorca. The latter three were murdered by Franco during Spain's fascist reign. Buñuel and a few other artists were able to flee for France and the US. Miró was among these exiles. It is also important to note that Miró's surrealist origins evolved out of "repression" much like all Spanish surrealist and majic realist work, especially since the Catalan ethnicity to which he pertained was subject to special persecution by the Franco regime. Also, Joan Miró was well aware of Haitian Voodoo art and Cuban Santería religion through his travels before going into exile. This led to his signature style of art making.

In 1926, he collaborated with Max Ernst on designs for Sergei Diaghilev. With Miró's help, Ernst pioneered the technique of grattage, in which he troweled pigment onto his canvases. Miró married Pilar Juncosa in Palma (Majorca) on October 12, 1929; their daughter Dolores was born July 17, 1931. Shuzo Takiguchi published the first monograph on Miró in 1940. In 1948–49, although living in Barcelona, Miró made frequent visits to Paris to work on printing his techniques at the Mourlot Studios (lithographs) and at the Atelier Lacourière (engravings). A close relationship lasting forty years developed with the printer Fernand Mourlot and resulted in the production of over one thousand different lithographic editions.

In 1959, André Breton asked Miró to represent Spain in The Homage to Surrealism exhibition together with works by Enrique Tábara, Salvador Dalí, and Eugenio Granell. Miró created a series of sculptures and ceramics for the garden of the Maeght Foundation in Saint-Paul-de-Vence, France, which was completed in 1964.

Throughout the 1960s, Miró was a featured artist in many salon shows assembled by Maeght that also included works by Marc Chagall, Giacometti, Brach, Cesar, Ubac, and Tal-Coat.

Miró was among the first artists to develop automatic drawing as a way to undo previous established techniques in painting, and thus, with André Masson, represented the beginning of Surrealism as an art movement. However, Miró chose not to become an official member of the Surrealists in order to be free to experiment with other artistic styles without compromising his position within the group. He pursued his own interests in the art world, ranging from automatic drawing and surrealism, to expressionism and Color Field painting.

Miró's oft-quoted interest in the assassination of painting is derived from a dislike of bourgeois art of any kind, used as a way to promote propaganda and cultural identity among the wealthy. Specifically, Miró responded to Cubism in this way, which by the time of his quote had become an established art form in France. He is quoted as saying "I will break their guitar," referring to Picasso's paintings, with the intent to attack the popularity and appropriation of Picasso's art by politics.

"The spectacle of the sky overwhelms me. I'm overwhelmed when I see, in an immense sky, the crescent of the moon, or the sun. There, in my pictures, tiny forms in huge empty spaces. Empty spaces, empty horizons, empty plains - everything which is bare has always greatly impressed me." - Joan Miró, 1958, quoted in Twentieth-Century Artists on Art.

In an interview with biographer Walter Erben, Miró expressed his dislike for art critics, saying, they "are more concerned with being philosophers than anything else. They form a preconceived opinion, then they look at the work of art. Painting merely serves as a cloak in which to wrap their emaciated philosophical systems."[citation needed]