Although previous studies have extensively explored the relationship between corporate social responsibility (CSR) and various organizational outcomes, the nuanced effects of internal and external CSR on different facets of employee engagement remain under-explored. This study examines how internal and external CSR affect employee engagement across physical, emotional, and cognitive dimensions. Drawing upon the stakeholder literature, we argue that CSR activities tailored to internal stakeholders may resonate more directly with employees, thereby enhancing their overall engagement. We analyze employee engagement levels and perceptions of CSR among 277 employees in the Chinese global rubber industry through an online survey. Our analysis reveals that internal CSR only improves affective emotional engagement, while external CSR positively influences all dimensions of employee engagement. Notably, we find that the impact of external CSR on employee engagement is more substantial than that of internal CSR. We explain these results by linking them to the literature on CSR and employee engagement, and our results also offer important managerial implications for promoting employee engagement.