Cloud-based big data governance is now a key management issue among organizations in South Africa that aim to enhance the security of their data, regulatory compliance, the effectiveness of their information management, and evidence-based decision-making. This paper examines the impact of organizational readiness for technology, data protection, and compliance practices on the big data decision-making abilities of South African companies, where the effectiveness of big data information management and cloud scalability solutions serve as mediation and moderation variables, respectively. A quantitative cross-sectional research design was used, and 500 professionals in the field of cloud-related work were used as the primary data. Partial Least Squares Structural Equation Modeling was used to analyze the proposed model with the help of Smart-PLS. The results indicate that organizational readiness for technology, data security, compliance practices, and cloud scalability solutions have positive effects on big data decision-making capabilities in the cloud-based organizational setting in South Africa. The effectiveness of big data information management is also a notable mediating variable, as it elaborates how organizational and technological variables are transformed into better decision-making ability. In addition, cloud scalability solutions enhance the influence of organizational preparedness, data protection, and compliance procedures on big data decision-making abilities. The study adds to the body of management and digital governance by introducing an integrated model. In practice, the results offer practical advice to managers, IT leaders, compliance officers, and cloud service professionals in South Africa to design secure, scalable, and governance-oriented cloud data management systems that facilitate strategic decision-making.