This publication provides a comprehensive assessment of how sustainable, stakeholder-driven seaweed supply chains can strengthen climate resilience and food security across APEC economies. It analyzes regional production trends, supply-chain bottlenecks, climate-related risks, and governance gaps, drawing on literature reviews, surveys, key-informant interviews, and expert consultations. The report highlights best practices from Indonesia; Japan; and Korea to illustrate community-centered governance, science-based carbon certification, and advanced value-chain development. Key outcomes include identified development needs across production, post-harvest handling, processing, trade, and institutional systems, as well as strategic policy recommendations for enhancing climate adaptation, supporting equitable blue-carbon pathways, and upgrading high-value seaweed industries. The publication ultimately offers a roadmap for building resilient, inclusive, and sustainable seaweed systems across the APEC region.