Assemblage is an artistic process in which a three-dimensional artistic composition is made from putting together found objects.

The origin of the word (in its artistic sense) can be traced back to the early 1950s, when Jean Dubuffet created a series of collages of butterfly wings, which he titled assemblages d'empreintes. However, both Marcel Duchamp and Pablo Picasso had been working with found objects for many years prior to Dubuffet. They were not alone, alongside Duchamp the earliest woman artist to try her hand at assemblage was Elsa von Freytag-Loringhoven, the Dada Baroness, and one of the most prolific, as well as producing some of the most exciting early examples, was Louise Nevelson, who began creating her sculptures from found pieces of wood in the late 1930s.

In 1961, the exhibition "The Art of Assemblage" was featured at the New York Museum of Modern Art. The exhibition showcased the work of early twentieth century European artists such as Braque, Dubuffet, Marcel Duchamp, Picasso, and Kurt Schwitters alongside Americans Man Ray, Joseph Cornell and Robert Rauschenberg, and also included less well known American West Coast assemblage artists such as Wallace Berman, Bruce Conner and Edward Kienholz. William C Seitz, the curator of the exhibition, described assemblages as being made up of preformed natural or manufactured materials, objects, or fragments not intended as art materials