The aim of the article is to present the history of research on the categories of “political actor” and “political agency” conducted by Polish political scientists. The article shows how they were defined and how the theories of society and politics prevalent at a given time shaped their understanding. Initially, both categories alluded to the collective vision of activity, to finally appreciate the role of individuals in initiating activity. The way researchers viewed the significance of political actors was changing over time as well; at the beginning, social classes and subsequently large groups were seen as crucial, while individuals were only eventually recognised as the source of agency. The article demonstrates that both categories have changed over the years, adapted to new social order, social structure and, in particular, to the ideologies prevalent in society. The article pays special attention to the concepts developed by Mirosław Karwat and Andrzej Czajowski.