We aim to develop a new optimization-based approach for the strategic planning of a renewable hydrogen supply system using onshore and offshore wind energy. To achieve this goal, we develop an optimization model to design and analyze a wind-powered hydrogen supply (WPHS) system using a mixed-integer linear programming technique. In this model, we include decision variables to account for a wide range of issues regarding the proposed system, from the technical selection of the wind turbine and wind farm layout design to strategies for onshore/offshore wind farm and hydrogen supply network development. To illustrate the capability of the proposed approach, we present a case study pertaining to the design of the WPHS system for the road transportation sector of Jeju Island, Korea. Using the proposed approach, we are able to i) identify the configuration and operational practices of an optimal WPHS system, ii) analyze the cost distribution and major cost drivers through economic evaluation, and provide decision-making guidance to stakeholders and policy makers for planning an economically viable and a sustainable hydrogen supply system using various policies to encourage offshore wind farm development. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.