Jackson Pollock in 1950

Action painting, sometimes called gestural abstraction, is a style of painting in which paint is spontaneously dribbled, splashed or smeared onto the canvas, rather than being carefully applied. The resulting work emphasizes the physical act of painting itself.

The style was widespread in the 1950s and 1960s, and is closely associated with abstract expressionism (some critics have used the terms action painting and abstract expressionism interchangeably). A comparison is often drawn between the American action painting and the French tachisme.

The term was coined by the American critic Harold Rosenberg in 1952, and signaled a major shift in the aesthetic perspective of New York School painters and critics. While abstract expressionists such as Jackson Pollock and Willem de Kooning had long been outspoken in their view of a painting as an arena within which to come to terms with the act of creation, earlier critics sympathetic to their cause, like Clement Greenberg, focused on their works' "objectness." To Greenberg, it was the physicality of the paintings' clotted and oil-caked surfaces that was the key to understanding them as documents of the artists' existential struggle.

Rosenberg's critique shifted the emphasis from the object to the struggle itself, with the finished painting being only the physical manifestation, a kind of residue, of the actual work of art, which was in the act or process of the painting's creation.

Over the next two decades, Rosenberg's redefinition of art as an act rather than an object, as a process rather than a product, was influential, and laid the foundation for a number of major art movements, from Happenings and Fluxus to Conceptual and Earth Art

In an Aesthetic Realism study of Pollock's painting Number One 1948, Lore Elbel-Bruce shows how the aesthetic effect of this quintessential example of action painting arises from the way it is at once abandoned and accurate — that is, puts together the very opposites that "struggle" or are in conflict not only in the artist but in every individual.