This comprehensive review emphasises recycled milled fibres’ sustainability, waste reduction, and cost savings in aerospace applications. The industrialization and prospective uses of recycled fibre-reinforced plastics FRP products, as well as cutting-edge fibre recycling and re-manufacturing processes, are discussed. The mechanical properties of milled fibre composites are reviewed for sustainable applications. A desire for a circular economy is transforming composites to reduce waste and promote sustainability. Fibre-reinforced plastics (FRPs) need innovative recycling methods to remain high-performance and environmentally friendly. Strategies to help the composites industry meet rising demand and strict environmental regulations are explored. Manufacturing of composite recycling conserves energy and materials, making it sector-wide. Due to the reclamation process impacting their performance milled fibres are typically not used for primary structural materials and are relegated to low-value applications. Therefore, the rigorous testing and qualification of these fibres, and their composites, is required. This will provide confidence in these materials' performance benefits and limitations and provide industry-wide uptake. The lack of a centralised body of knowledge on milled fibre applications is also addressed, and an overview of R&D efforts, along with financial and logistical considerations for industrial implementation, is provided in the review.