Caribbean small island developing States face a complex convergence of structural vulnerabilities that profoundly threaten their long-term development. These challenges include acute climate vulnerability (manifesting as hurricanes, sea-level rise, salination, biodiversity loss, sargassum influxes and drought), limited land and natural resources, high dependence on imported food, and challenging geographic and economic isolation due to small domestic markets. Compounding these issues are significant fiscal constraints, high debt levels and persistent brain drain, which collectively limit investment in long-term resilience and development strategies. While Caribbean SIDS increasingly recognize the transformative potential of STI to drive resilience, sustainability and economic diversification, this crucial input remains critically underfunded, underrepresented and inadequately integrated into national, regional and global policy settings and planning frameworks. The Caribbean allocates a mere 0.1–0.2% of its GDP to research and development, substantially below the 2% or more invested by leading science economies like the Republic of Korea or the United States of America. This underinvestment, heavily concentrated in a few larger economies within Latin America and the Caribbean, leaves smaller economies with minimal scientific capacity. Furthermore, existing national STI strategies are often outdated or disconnected from core sustainable development policies, such as those addressing climate change, biodiversity, energy production or sustainable tourism.