The demand for lightweight, high-performance, and sustainable structures has driven a growing interest in hybrid and multi-material systems that strategically combine metals, polymers, and fibre-reinforced composites. This session focuses on the latest advances in the design, manufacturing, and characterisation of such structures, addressing challenges related to joining and interfaces, residual stress control, damage tolerance, and long-term durability. Contributions covering experimental and numerical approaches, hybrid joining techniques (adhesive bonding, welding, mechanical fastening), and integrated digital design methods are particularly welcome. The session also encourages works on multi-scale modelling, topology optimisation, and AI-assisted frameworks for the design and performance prediction of hybrid structures across aerospace, automotive, marine, and energy applications. The aim is to foster interdisciplinary discussion and collaboration toward next-generation lightweight, sustainable, and damage-tolerant structural solutions.