Unmanned aerial vehicle (UAV) platforms have been widely studied worldwide over the past decades. It is predicted that it will be a trending topic for the next decades as well. When the development of unmanned aerial vehicles is analyzed, it is seen that they were initially used and developed only for military purposes. However, thanks to the widespread use of four-motor multirotors and the relatively simple operation protocols introduced by electric motors, the number of unmanned aerial vehicles used for civilian purposes has increased much faster than for military purposes and has already surpassed this number. Battery-powered only electric UAVs cannot stay in the air for long periods due to their high battery weights. Today, fuel cells are one of the topics being studied to increase the flight time of electric UAVs. Due to their high efficiency, fuel cells can significantly increase the flight time. In this study, fuel cell UAV studies in the open literature are reviewed and the differences between them are analyzed.