Upcycling, also known as creative reuse, is the process of transforming by-products, waste materials, useless, or unwanted products into new materials or products perceived to be of greater quality, such as artistic value or environmental value.

Upcycling is the opposite of downcycling, which is the other face of the recycling process. Downcycling involves converting materials and products into new materials of lesser quality. Most recycling involves converting or extracting useful materials from a product and creating a different product or material.

The terms upcycling and downcycling were first used in print in an article in SalvoNEWS by Thornton Kay quoting Reiner Pilz and published in 1994.