The BRICS nations-Brazil, Russia, India, China, and South Africa-recently committed, as enshrined in their 2024 Declaration, to jointly promoting a global framework for data governance. As the number of new BRICS group members grows, now including six new members and nine new partner countries, emerging economies are increasingly shaping the dynamics of data governance and digital cooperation.Personal Data Architectures in the BRICS Countries provides a comprehensive analysis of personal data governance frameworks within the BRICS nations and explores the potential for enhanced cooperation in the management and regulation of international data flows. Drawing on the pioneering research of the CyberBRICS project, each chapter in this volume delves into the unique legislative landscapes of the member countries, highlighting significant regulatory developments such as Brazil's General Data Protection Law (LGPD), Russia's evolving privacy and data localisation regulations, India's Digital Personal Data Protection Act 2023 and its Data Empowerment and Protection Architecture, China's Personal Information Protection Law (PIPL), and South Africa's Protection of Personal Information Act (POPIA). The authors examine the challenges each nation faces in harmonising data protection with economic growth and technological innovation, while addressing issues of national sovereignty, cybersecurity, industrial policy, and international coordination. Pioneering and timely, this volume offers concrete solutions and mechanisms for sustainable transborder data transfers and digital trade, emphasising the importance of fostering legal interoperability and shared governance principles. By proposing model contractual clauses and strategic cooperation pathways, the book advocates for a shared BRICS stance on personal data protection, aiming to balance data subject rights with the imperatives of cybersecurity and digital sovereignty in a connected digital economy.