Citizen participation is one of the leading values of both democracy and political science. The debates on participation, which initially demonstrated its impact in the field of political science, stem from the problems of legitimacy caused by representative democracy. The main element in these debates, which also soon spread to the field of public administration, is the active participation of citizens in decision making processes related to public policies. However, the role of citizen in the public administration approach of the 21st century is accepted to be more than that. In this study, it is aimed to discuss the transforming role of the citizen in the context of participation. For this, firstly, the concepts of citizenship, participation, participatory democracy and participatory public administration are determined, and then the roles of citizen in two basic public administration models (Classical Public Administration and New Public Management) are examined. Thirdly, the role of co-producer citizen in the new term (Post – New Public Management) is mentioned and the transformation in public administration is evaluated through the arguments in these three models. Finally, the examples of co-production practices and the concrete roles of citizens in this context are listed. The most obvious conclusion from this point of view is that citizens are no longer expected to participate not only in decision making processes, but also in the production and delivery of the public service.