Internationalization of the curriculum (IoC) is widely proclaimed as a priority across universities, but in the Global South, the disconnect between policy statements and what happens in curricula remains substantial and insufficiently understood. This article investigates why that gap endures at the University of South Africa (UNISA), the continent’s largest open, distance, and e-learning (ODeL) institution. Drawing on critical theory and Leask’s framing of IoC, and viewing curriculum as a layered construct intended, enacted, and achieved, the study used semi-structured interviews with 39 purposively selected participants (30 students, five lecturers, three senior managers, and the director of the international office) alongside documentary analysis of national and institutional policy texts, interpreted through reflexive thematic analysis. The findings point to three interconnected sets of constraints: systemic and resourcing limitations; policy and political obstacles, including claims of curriculum sovereignty and unrealized institutional policies; and pedagogical and cultural impediments, especially the discretionary use of IoC, an ongoing Eurocentric orientation, and a lack of explicit aims and assessed outcomes. These constraints do not function in isolation; instead, they interact in a mutually reinforcing loop of institutional inertia, in which limited resources preserve existing pedagogical arrangements, thereby dampening pressure to implement change. The study advances comparative and international education by arguing that the policy–practice gap in an African ODeL context is not simply a technical implementation problem but reflects a political economy of curriculum, and by clarifying the circumstances in which internationalization and decolonization are experienced as competing agendas rather than complementary ones. The article concludes with implications for institutional leaders, policymakers, and academic developers working in similar distance-education and Global South contexts.