The blue economy which involves fisheries, maritime trade, and coastal tourism sector is a critical element of food security, livelihoods and inclusive economic growth. Nevertheless, integrity of the supply chain, data, and transparency have been continuous obstacles of the sector, destabilizing trust and sustainability. These issues of governance and traceability have been promising solutions posed by the blockchain technology that is inscribed with key features of decentralization, immutability, and transparency. This chapter delves into how blockchain can be applied in improving visibility and regulatory compliance and stakeholder accountability in the blue economy supply chain. Based on real-life case studies, it explains how decentralized trust mechanisms could become a tool to empower and benefit the communities, enhance traceability, and result in ethical sourcing. The chapter also looks at adoption barriers such as interoperability limitation, energy intensive, and regulatory ambiguity and the future research directions. Finally, the analysis helps to expand the growing debate around digital transformation and ocean management, pointing to the possible contribution of blockchain to the establishment of sustainable and equitable marine systems.