Decoupage or découpage (; French: [dekupaʒ]) is the art of decorating an object by gluing colored paper cutouts onto it in combination with special paint effects, gold leaf, and other decorative elements. Commonly, an object like a small box or an item of furniture is covered by cutouts from magazines or from purpose-manufactured papers. Each layer is sealed with varnishes (often multiple coats) until the "stuck on" appearance disappears and the result looks like painting or inlay work. The traditional technique used 30 to 40 layers of varnish which were then sanded to a polished finish.

Three dimensional decoupage (sometimes also referred to simply as decoupage) is the art of creating a three-dimensional (3D) image by cutting out elements of varying sizes from a series of identical images and layering them on top of each other, usually with adhesive foam spacers between each layer to give the image more depth. Pyramid decoupage (also called pyramage) is a process similar to 3D decoupage. In pyramid decoupage, a series of identical images are cut into progressively smaller, identical shapes which are layered and fixed with adhesive foam spacers to create a 3D "pyramid" effect.

A person who does decoupage is known as a decoupeur, or "cutter".