BIOntier- BreakIng FrOntiers in Sustainable and Circular Biocomposites with High Performance for Multi-Sector Applications BIOntier addresses environmental challenges by developing next-generation bio-based composites (BioC) that are sustainable, lightweight, recyclable, and cost-effective. These advanced materials offer enhanced thermal, mechanical, and chemical performance, along with key functionalities such as fire, corrosion, and impact resistance, and structural health monitoring. The project also improves green manufacturing processes to increase efficiency and reduce environmental impact. BIOntier will validate six BioC-enabled use cases across strategic sectors including automotive, aerospace, hydrogen energy, and water treatment, advancing technologies from TRL 4–5 to TRL 6–7. With a consortium of 25 partners from 12 countries, including leading OEMs, industries, research institutions, and SMEs, BIOntier supports the EU’s circular bioeconomy strategy, paving the way for industrial innovation and strong market impact across Europe.