Background: South Africa faces significant socio-economic challenges, with unemployment rate. This highlights the need for economic strategies to generate employment, and start-ups are crucial in this context, as they foster innovation, create jobs and increase competitiveness.Aim: The study aims to investigate how digital innovation hubs (DIHs) influence start-up growth, focusing on their roles and functions.Setting: The research is set within the context of DIHs in Africa, specifically examining the 12 DIHs established under the AEDIBNET programme.Methods: A qualitative methodology was employed, using semi-structured interviews with six DIH managers and 28 entrepreneurs or start-up founders.Results: Supporting start-up growth, holistic development support and integrated ecosystem enhancement by DIHs emerged as key themes. These factors foster a conducive environment for innovation and sustained growth.Conclusion: Digital innovation hubs play a crucial role in supporting start-up growth by providing comprehensive and integrated support systems. Their functions collectively enhance start-up growth.Contribution: This study fills a critical gap in the existing literature on DIHs, offering empirical insights into their impact on start-up growth within the African context. The findings provide valuable implications for policymakers, practitioners and researchers aiming to foster the growth of start-ups. Additionally, the study integrates and expands upon knowledge spillover theory, institutional theory and cluster theory. It demonstrates how DIHs facilitate knowledge sharing, provide formal support structures, foster informal networks, and create and sustain entrepreneurial clusters.