This volume presents state-of-the-art methods and emerging solutions for retrofitting buildings and infrastructure to meet the dual imperatives of decarbonisation and resilience. By reframing retrofitting as a multi-performance design problem, the book integrates structural safety, functional recovery, life-cycle environmental impact, and risk reduction under both single- and cascading-hazard scenarios. Its chapters cover several topics on sustainable retrofitting for buildings, including but not limited to: performance-based assessment of existing structures, strengthening materials and techniques for seismic areas, low-carbon seismic retrofit solutions such as Cross-Laminated Timber (CLT)-based infills, fire-safety retrofitting and data-driven inspection and monitoring for energy and comfort retrofits.Sustainable Retrofitting Towards Resilient Buildings and Infrastructure provides a coherent toolbox for practitioners, researchers, and decision-makers gain to design retrofit interventions that are technically robust, economically defensible, and aligned with climate and societal objectives. It addresses enabling governance through proportional-improvement legal frameworks and provides heritage-focused case studies from Italy. This book is also suitable as a textbook for graduate-level courses and professional training in seismic retrofit, sustainable construction, and multi-hazard resilience engineering.