<p>The growing search for sustainable alternatives to synthetic materials has established natural fibers as strategic elements for the development of environmentally friendly composites. This study critically reviews scientific advances in the field of natural fibers applied to sustainable composites, exploring trends, applications, and challenges shaping the future of this field. The work’s originality lies in its comprehensive bibliometric analysis of over two decades of international research, revealing not only the significant rise of lignocellulosic fibers as key players but also the pathways that connect mechanical properties, processing, sustainability, and industrial applications. The study organizes the scientific landscape into four thematic areas: sustainable materials, biocomposite properties, hybrid composites, and recycling, offering an integrated view that highlights both the potential for replacing synthetic fibers and the remaining barriers, such as water absorption and the need for advanced treatments. The central contribution of this work is to demonstrate that natural fiber composites, especially biocomposites and hybrids, are not only a viable alternative, but also a strategic solution for aligning materials innovation with global goals of sustainability, circular economy, and reduced environmental impact. The findings position natural fiber composites as critical to sustainable material development.</p>