The energy transition in the maritime sector requires sustainable solutions to reduce emissions and enhance the efficiency of port operations. In this context, hydrogen produced from renewable sources represents a promising pathway for the decarbonization of Mediterranean ports. This study presents a GIS-based model to assess the hydrogen production potential of major ports in the Mediterranean region. The analysis evaluates the integration of renewable energy sources, including solar, wind, and wave power, to drive electrolysis for hydrogen production. The developed model serves as a crucial tool for strategic planning and design, enabling the evaluation of different operational strategies and the integration of energy storage systems, such as batteries. It incorporates economic, energy, and environmental indicators to optimize system configurations and assess the feasibility of hydrogen production in different locations. A key focus is the minimization of the Levelised Cost of Hydrogen, providing insights into cost-effective approaches for sustainable port energy systems. Additionally, the study explores potential economic and regulatory mechanisms that could support the transition toward greener ports. The results highlight significant variations in hydrogen production potential across different ports, influenced by local renewable energy availability. The proposed approach helps identify the most suitable areas for hydrogen development, supporting decision-making processes for energy planning in Mediterranean ports. This research contributes to the broader goal of port decarbonization and facilitates the transition toward a more sustainable hydrogen-based economy.