Climate change poses significant risks to children, particularly in Small Island Developing States (SIDS), where geographic isolation, limited resources, and reliance on climate-sensitive sectors intensify vulnerabilities. This study pilots the Children’s Climate Risk Index – Disaster Risk Model (CCRI-DRM) to assess child-specific vulnerability to environmental hazards in Saint Kitts and Nevis at the parish level. Using a cross-sectional, subnational risk assessment approach, the model integrates locally sourced and global datasets to evaluate both exposure to climate and environmental hazards and underlying socio-economic vulnerabilities. The CCRI-DRM is structured around two pillars: Exposure to Climate and Environmental Hazards, Shocks, and Stresses, encompassing nine hazard components such as drought, flooding, tropical winds, vector-borne diseases, extreme heat, and air pollution; and Vulnerability to Climate and Environmental Shocks, captured through indicators of child health, education, and poverty. Normalized and aggregated risk scores from both pillars form a composite index that provides fine-grained insight into spatial disparities across the country’s 14 parishes. Results reveal substantial geographic variation, with Saint Paul Capisterre and Saint George Basseterre identified as the highest-risk areas due to the combined effects of extreme hazard exposure and systemic socio-economic vulnerabilities. These findings underscore the urgent need for targeted interventions that address both environmental risks and the structural conditions that amplify child vulnerability. This study demonstrates the utility of the CCRI-DRM in a SIDS context, showing how a refined, granular model can translate high-level climate policy frameworks into actionable, locally relevant adaptation and disaster risk reduction measures. By identifying where and why risks are highest, the CCRI-DRM offers a scalable approach for improving child-centered climate risk assessment in understudied, climate-vulnerable regions and for bridging the gap between policy and implementation.