Climate change poses existential threats to global agricultural systems, undermining productivity, degrading natural resources, and exacerbating food insecurity across vulnerable regions. Climate-smart agriculture (CSA) has emerged as an integrated approach to transform and reorient agricultural systems, effectively supporting development and ensuring food security under changing environmental conditions. This review synthesizes current knowledge on CSA principles and practices, examining their dual role in enhancing agricultural productivity while building environmental resilience and mitigating greenhouse gas emissions. The analysis encompasses sustainable farming methodologies including conservation agriculture, agroforestry, integrated crop-livestock systems, and precision nutrient management, alongside technological innovations such as remote sensing, Internet of Things (IoT)-enabled monitoring, climate forecasting tools, and decision-support systems that enable data-driven resource optimization. Evidence demonstrates that integrated CSA approaches significantly improve soil carbon sequestration, water-use efficiency, yield stability, and biodiversity conservation while reducing agriculture's environmental footprint. However, widespread adoption faces substantial barriers including institutional constraints, technological access limitations, financial hurdles, and inadequate extension services, particularly affecting smallholder farmers in developing regions. Future progress requires targeted investments in research and innovation, supportive policy frameworks, enhanced farmer capacity building, and strengthened institutional mechanisms that facilitate technology transfer and practice adoption. Achieving sustainable food systems under climate stress necessitates the systematic integration of CSA principles into national agricultural strategies and global sustainability frameworks.