This Special Issue of Materials presents a comprehensive exploration of eco- and biomaterials, focusing on their experimental research and computational analysis. As sustainability becomes a critical focus in engineering and medical fields, this collection highlights the innovative use of natural and synthetic materials that interact with organic tissues and support sustainable construction practices. The studies featured here provide in-depth insights into the mechanical properties, structural integrity, and durability of these materials, combining empirical evidence with advanced computational models. This Special Issue is an essential resource for scientists, engineers, and industry professionals interested in the latest advancements in sustainable materials, offering practical applications and methodologies that enhance the development of eco-friendly and biologically compatible materials. Perfect for those seeking to stay at the forefront of sustainable material science, this collection serves as a vital reference for both academic research and industrial application.