This study analyses the social position of women based on Simone de Beauvoir’s work ‘The Second Sex – The Age of Marriage’. The research examines how women have been pushed into the position of ‘the other’ in historical and cultural processes, using concepts from feminist theory and existentialist philosophy. The subject of the study is how the institution of marriage shapes women’s identity and its impact on their struggle to become individuals. The importance of the research lies in revealing how women are controlled through gender roles and how these roles reproduce the patriarchal order. The aim of the research is to show how womanhood is constructed not only biologically but also through cultural, ideological, and religious structures in Simone de Beauvoir’s work. To this end, a qualitative method was used, and text-based descriptive analysis was preferred. Beauvoir’s The Second Sex was examined as the primary source, and the works of thinkers such as Zehra Y. Dökmen, R.W. Connell, Inge Stephan, and Josephine Donovan were evaluated as secondary sources. According to the findings, womanhood has been narrowed down by social gender roles, the institution of marriage, and cultural norms. According to Beauvoir, women are defined as the opposite and complement of male subjects and therefore pushed into the position of the other rather than being individuals. Marriage provides women with apparent security, but in fact limits their physical and economic freedom. Heidegger’s concept of “das Man” and Sartre’s concept of “being-for-itself” are used to explain women’s social alienation. In addition, Stephan’s analyses reveal the psychological dimensions of this otherness. It shows that female identity is not merely a biological reality, but a construct built on gender roles imposed by patriarchal society, cultural norms, and religious codes. According to Beauvoir’s analysis, women have been deprived of their right to be individuals and constantly pushed into the position of ‘the other’ because they are defined as the opposite and complement of men. The institution of marriage, while seemingly providing security and status, in reality reduces women to the roles of wife, mother, and servant. A woman’s body, desires, and decisions are controlled by social norms and the male gaze. As a result, marriage is not a space of equality but a space of power that reproduces male supremacy. A woman’s subjectification is only possible through economic independence, individual awareness, and the questioning of patriarchal norms. The historical process of feminist movements also shows that this liberation can only be achieved through collective effort, not individual effort.