As the sporting industry has become more professionalised, there have been an increased number of studies focused on corporate social responsibility (CSR) engagement within this sector. However, with unique aspects of professional sport organisations and limited studies on this in developing market contexts, this paper reports on a study that aimed to investigate the impact of environmental factors and stakeholders that have an impact on sustainable CSR engagement in the South African professional sport industry. Following an interpretivist philosophy, this study adopted a qualitative research approach to collect the primary data. Key stakeholders were strategically selected from six South African professional sport organisations and ten in-depth interviews were conducted. This inquiry revealed that several internal and external environmental factors influence sustainable CSR engagement by professional sport organisations, namely, (1) internal objectives, funds, people and resources and (2) external uncontrollable factors, economy, and community awareness. The study also found that corporate partnerships, non-corporate partnerships and targeted communities were the main stakeholder types involved in CSR activities. The study, therefore, expands the understanding of CSR engagement within the professional sport industry in South Africa, also contributing to CSR practice and policy within this sector by proposing the engagement in more sustainable CSR initiatives.