The Digital Silk Road (DSR) was launched by China in 2015 as part of the Belt and Road Initiative (BRI), presented as a project aimed at enhancing global digital connectivity and technological cooperation. We argue that this typically liberal perspective is contestable and fails to capture the full scope of the DSR, which encompasses geopolitical and security considerations. Accordingly, this study seeks to address a significant gap in the literature regarding the expansion and effects of the DSR, particularly in Brazil and South Africa, thereby contributing to a more nuanced understanding of China’s global digital strategy. Building on this premise, this chapter explores the expansion, dimensions, and effects of the DSR in the South Atlantic region through an analysis of two paradigmatic and contrasting case studies: Brazil, which, despite not being formally part of the BRI, functions as a de facto partner of China and a member of the DSR, and South Africa, which is a participating state in the BRI but not formally included in the DSR, although it remains a target of Chinese digital investment. Adopting a predominantly qualitative approach and guided by our research question—How has China expanded the DSR to the South Atlantic, specifically in Brazil and South Africa?—we find that the DSR plays a dual role, both as a mechanism for development and as an instrument of strategic action that poses significant risks in terms of digital security for the countries within this region.