Fast fashion is a term used to describe a highly profitable and exploitative business model based on replicating catwalk trends and high-fashion designs, mass-producing them at low cost. Oftentimes, this entails exploiting workers in inhumane conditions. The term fast fashion is also used to generically describe the products of the fast fashion business model.

The fast fashion business model was made possible during the late 20th century as manufacturing of cloth became cheaper and easier, through new materials like polyester and nylon, efficient supply chains and quick response manufacturing methods, and inexpensive labour in sweatshop production and low-labour protection bulk clothing manufacturing industries in South, South East, and East Asia.

Companies like H&M and Zara built business models based on inexpensive clothing from the efficient production lines to create more seasonal and trendy designs that are aggressively marketed to fashion-conscious consumers – because these designs are changing so quickly and are so cheap, consumers buy more clothing than they would previously, so expectations for those clothes to last decrease. Stealing designs is also common.