This paper offers a critical theoretical review of the functionalist approach to peace-building, with particular attention to the integration of gender perspectives in post-conflict societies. While functionalism has traditionally emphasized institutional interdependence and normative cohesion as foundations for social stability, it has often overlooked structural inequalities, especially those related to gender. This paper addresses that gap by synthesizing classical functionalist theory with contemporary gender-sensitive scholarship and recent empirical studies (2020–2025). Drawing on insights from sociology, peace and conflict studies, and feminist institutionalization, the paper argues that gender inclusion is not merely a normative imperative matter, but a functional necessity for sustainable peace, and societal development. The paper conducted a descriptive comparative content analysis study of selected African countries or societies with similar cases, such Nigeria, Rwanda, South Sudan, and Liberia. The paper is qualitative research method using secondary data source and AI as research assistant. This paper demonstrates how women’s participation enhances institutional legitimacy, strengthens informal and formal peace mechanisms, and contributes to long-term social cohesion. The study further evaluates emerging trends in global peacebuilding, including the stagnation of women’s representation in formal agreements and the growing significance of grassroots networks and inter-sectional approaches. It concludes by proposing a framework for integrating gender into functionalist peace-building and outlines policy and research implications for advancing inclusive and resilient post-conflict reconstruction. The paper uses combined theories of Functionalist Peace Theory, Feminist Theory and Women, Peace & Security as Feminist Theory of the international Women agenda works of three distinguished scholars of J. Ann Tickner 1992, Cynthia Enloe 1989 & Carol Cohn 1987.