This book encapsulates the intellectual rigor and cross-disciplinary collaboration showcased at a global forum dedicated to advancing the understanding and application of geotechnical systems in sustainable infrastructure development. Proceedings of the 1st International Conference on Innovations and Sustainability in Civil Engineering: Shaping Tomorrow’s Infrastructure (ISCESTI—2025), held from May 14–16, 2025, at the National Institute of Technology (NIT) Patna, present a compelling compilation of pioneering research, emerging technologies, and sustainable practices in the field of geotechnical engineering. It addresses a broad spectrum of contemporary issues, from ground improvement techniques and geosynthetics to the impacts of climate change on soil behavior and foundation design. The contributions explore innovative approaches to soil stabilization, earthquake geotechnics, underground construction, and slope stability analysis, integrating field investigations, laboratory experimentation, and advanced numerical modeling. Particular emphasis is placed on eco-friendly solutions such as bio-mediated ground improvement, reuse of industrial waste materials in geotechnics, and the development of resilient and adaptive foundation systems. This book also highlights the role of digital and data-driven technologies—such as machine learning, remote sensing, and geotechnical instrumentation—in enhancing subsurface characterization, predictive modeling, and risk mitigation strategies. Case studies and practical insights illustrate the application of geotechnical innovations in real-world infrastructure projects under challenging environmental and geohazard conditions. Serving as a vital resource for geotechnical engineers, researchers, academicians, and infrastructure policymakers, this book provides actionable frameworks and future-oriented solutions to address the evolving demands of urbanization, climate adaptation, and sustainability. It positions geotechnical engineering at the forefront of building resilient, safe, and environmentally responsible infrastructure for the generations to come.