Wind power development as an alternative to fossil fuels or nuclear energy is currently a challenge for many countries. Wind power development often leads to conflicts between different actors. This case study examines conflict about wind power projects in forested landscapes in Rhineland-Palatinate, Germany, and Maine, USA. Specifically, actor perspectives on polycentric governance and its legitimacy to manage such complex conflicts were evaluated based on 40 qualitative, semistructured interviews with actors engaged in wind power decisions from various sectors. Polycentric governance has been advocated by many to alleviate conflicts and arrive at sustainable solutions in complex resource management settings. Polycentric governance systems of wind power issues were regarded positively and considered as having high legitimacy by interview participants. Even though individuals had varied perceptions, the combined perceptions of the two polycentric systems in Rhineland-Palatinate and Maine and the factors that constitute legitimacy in wind power governance were similar in both cases.