This case study analyses the constrained agency of South Sudanese women in formal political participation and grassroots peacebuilding between 2021 and 2026. It investigates the persistent disparity between the rhetorical commitment to women’s inclusion within the 2018 Revitalised Peace Agreement and their continued marginalisation from substantive decision-making during its implementation. Employing a rigorous qualitative methodology, the research undertakes a thematic analysis of key policy documents and triangulates this with data from semi-structured interviews conducted with women activists, politicians, and community leaders across Juba and two selected states. The findings demonstrate that while women are indispensable in sustaining local-level reconciliation and humanitarian response, their agency is systematically circumscribed by a confluence of entrenched patriarchal norms, targeted political violence, and deliberate economic exclusion. The study contends that institutionalised participation mechanisms frequently co-opt women’s roles into a technical, checkbox exercise, thereby stifling transformative leadership. Its primary contribution lies in centring African feminist perspectives to critique externally imposed models of participation and to advocate for frameworks grounded in South Sudanese women’s lived realities and existing peace infrastructures. The conclusions necessitate a fundamental reorientation of international peacebuilding support, moving beyond symbolic representation towards the dismantling of structural barriers that perpetuate women’s political and economic disenfranchisement.