This open access book brings together concrete analyses from around the world, spanning various scales, that shed light on strategies for implementing essential energy and climate transitions within the broader context of UN Sustainable Development Goal (SDG) imperatives. Specifically, the book exemplifies the advancement, adaptation, and utilization of energy systems models to address intricate policy issues around pathways to achieve net-zero emissions, enhance energy security, optimize investments, and understand their societal implications. It explores the intricate connections between the SDGs concerning energy, climate action, and other developmental priorities such as employment and economic growth, industrial innovation, urban development, responsible consumption and production, and collaborative partnerships. Organized into four sections, the book illustrates the necessary adjustments of energy system models to guide SDGs, evaluates the role of modeling to advance both renewable energy and energy security, and showcases how energy systems are harnessed to engage with international, national, and local policymakers. This book is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.