Textiles made of blended cotton/polyester fibers have a huge share of the markets nowadays. The desirable properties of these blends made them a popular choice for both producers and consumers. However, at the end of life, this blended textile waste is often being disposed of in landfills in many parts of the world, since the fibers are hard to be fractionated and/or separated from each other and sorted according to their type, which hinders their recyclability and re-introduction to the supply chain. A significant loss of resources and big environmental impacts are only few consequences of these practices. In this article, we highlight the state of the art of fractionation and separation of cotton/polyester blended textile waste and the methods used in literature, which could be classified into mechanical, chemical and biological approaches. Additionally, we critically discuss the challenges facing these processes and their scaling-up, providing insights on how to overcome these challenges and the new initiatives in this regard, in order to contribute to the circularity and sustainability of the textile sector.