Sustainability in the water-energy-food nexus underscores the critical interplay between water, energy, and food systems, emphasizing the need for balance and harmony to ensure long-term environmental, social, and economic well-being. Water is essential for agricultural production and energy generation, while energy is required for water extraction, treatment, and distribution, as well as for agricultural operations. Similarly, food production demands both water and energy inputs. Sustainability comprises a holistic approach to development that recognizes the interconnectedness of environmental, economic, and social systems. It involves adopting long-term perspectives, making informed choices, and implementing policies and practices that promote resilience, harmony, and well-being for both present and future generations. Strategies to achieve sustainability include promoting water-efficient agriculture, investing in renewable energy sources, reducing food waste, and enhancing cross-sectoral collaboration and governance. By adopting sustainable practices in this nexus, societies can mitigate resource scarcity, reduce environmental degradation, enhance resilience to climate change, and promote equitable access to essential resources. Through this book, we attempt to enlighten the readers about the new concepts in this field of sustainability in the water-energy-food nexus. This book is an essential guide for both academicians and those who wish to pursue this discipline further.