This contributed book, as a part of a series of CERES publications, provides a multi-regional and cross-sectoral analysis of the interlinkages, challenges, and emerging responses in the areas of water security, climate change, and food systems, especially in a context marked by severe implications of the COVID-19 pandemic, increased climate vulnerability of many regions already water stressed, and an ambitious global action aiming at curbing climate change and restoring ecosystem. In the first set of chapters, the water, food, and environmental/climate security nexus is explored theoretically and by reference to empirical research covering many regions and sectors. In another set of chapters, the impacts of climate change on water resources and water-stressed regions are identified along with their implications for food systems and security. Other chapters of the volume identify the emerging solutions to the nexus challenges, mainly adaptation and mitigation options, governance and management approaches, technological and economic solutions, innovative farming and water management practices, etc. Most chapters scheduled for publication address timely and future-oriented topics, are based on empirical research particularly done in water-constrained and climate vulnerable countries from Asia, Africa, and the MENA region, and provide policy-oriented inputs and recommendations to guide change processes at multiple scales.