Fuel cells are considered the most promising path to increased endurance of electric powered small unmanned aircraft. Recent progress in fuel cell technology and hydrogen storage has resulted in several demonstrator platforms with formidable endurance. However, further research and development is needed to transition to widespread use. To help guide this changeover this paper presents a comprehensive overview of recent research activities, and highlights research challenges and opportunities. Firstly, benefits of fuel cells for unmanned vehicle propulsion are covered, and some challenges are identified. An overview of some notional demonstrator vehicles is given next to provide a panoramic view of progress made and the current state-of-the-art. Following this, research in fuel storage technology and hybridisation efforts are separately surveyed and discussed. Finally, some recommended future research areas are identified before conclusions are drawn. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.