Business model (BM) innovation driven by corporate social responsibility (CSR) has attracted considerable attention from scholars. However, the understanding of whether and how CSR influences BM innovation is limited. Therefore, this paper aimed to fill these gaps by exploring the influence of CSR on BM innovation through the mediating role of organizational legitimacy (OL). This paper proposed research hypotheses on the relationships among CSR, OL, and BM innovation and empirically tested these hypotheses by using the hierarchical regression analysis method with data collected from 186 firms. The results of this study show that both CSR and OL positively influence BM innovation. The results also show that CSR positively influences OL and OL mediates the relationship between CSR and BM innovation. This paper provides new insights into the relationship between CSR and BM innovation by answering questions of whether and how CSR influences BM innovation. This paper may help managers better understand how to link CSR and BM innovation.