In this thesis, I analyze the development of communist women’s activism in the interwar Kingdom of Serbs, Croats, and Slovenes/Kingdom of Yugoslavia, focusing on communist women’s individual and collective, similar, and diverse actions, trajectories, and emotions. Through an analysis of the official Yugoslav Communist Party and trade union documents, journal and newspaper articles, and communist women’s memoirs, which I situate within the history of communism, women’s and gender history, transnational history, and history of emotions, I investigate the evolvement of the political consciousness and self-identification of the two generations of communist women, seeking to understand the motivation for their political activism and their own understanding of it, as well as its effect on their private lives. I demonstrate that, against the background of the conditions imposed by the illegality of the Communist Party and, in particular, the King’s dictatorship, communist-inclined women fell into three groups: “organized communist women,” “fellow travellers,” and “individual-level sympathizers.” I show that the borders between these groups were fluid and that women, as their activism evolved, moved between these groups. My thesis aims to reconstruct the history of communist women’s activism, seeing these women as historical and political subjects whose individual and collective actions, motivations, and efforts made an important contribution to the broader interwar Yugoslav communist movement.