Connecting Communities Through Underground Infrastructure contains the contributions presented at the ITA-AITES World Tunnel Congress 2026 (Montréal, Canada, 15-21 May 2026). The papers reflect the full lifecycle of tunnelling and underground engineering projects, from strategic vision through operation and renewal . This book brings together the collective expertise of owners, designers, contractors, suppliers, consultants, researchers and academics from around the world, capturing the innovation, collaboration and technical excellence that define the tunnelling industry. The papers in this volume are organized into 5 key themes: Strategic Vision, Planning and Governance Ground Intelligence and Digital Integration Engineering Design and Underground Structures Construction Methods, Innovation and Delivery Commissioning, Operation and Asset Management Together, they provide a comprehensive reference to the state-of-practice and state-of-the-art in tunnelling and underground engineering, and a key resource for working professionals, decision makers, researchers and students.