This proceedings volume showcases the latest scientific and engineering advances in environmental geotechnology and sustainable engineering, addressing the urgent global need for innovative solutions to environmental degradation, climate change, resource scarcity, and resilient infrastructure development. Featuring peer-reviewed contributions from researchers and practitioners presented at EGRWSE-2026, the book highlights emerging technologies, interdisciplinary methodologies, and practical engineering applications that support sustainable development and environmental stewardship. The volume presents cutting-edge research on circular economy and waste valorization, contaminated site remediation, geoenvironmental characterization and monitoring, renewable energy geotechnics, nature-based and biotechnological solutions, sustainable infrastructure, climate-responsive geoengineering, and advanced ground improvement techniques. Combining fundamental research with laboratory studies, field investigations, modeling, and real-world case studies, the contributions demonstrate how scientific innovation can be translated into practical solutions to protect natural resources, improve infrastructure performance, and enhance environmental resilience. Structured around major thematic areas in environmental geotechnology and sustainable engineering, the book provides an overview of current research trends, technological developments, and future directions. This book can serve as an important reference for researchers, graduate students, practicing engineers, consultants, industry professionals, and policymakers seeking state-of-the-art knowledge and practical solutions to advance sustainable and resilient infrastructure, environmental protection, and responsible resource management in support of the United Nations Sustainable Development Goals.