Social movement entrepreneurs frame issues, mobilize movements, and shape movement organizations and strategies. John McCarthy and Mayer Zald introduced the concept of a social movement entrepreneur in their seminal essays on resource mobilization theory. They argued that movement entrepreneurs take the initiative to organize movements and sometimes even manufacture grievances that aid mobilization. While resource mobilization theory links movement entrepreneurs to the professionalization of social movements, other approaches focus on moral entrepreneurs who provoke moral outrage. Scholars have examined the impacts of movement entrepreneurs in a wide range of movements and organizational contexts, including formal and informal organizations, e-movements, and institutional settings.