More and more firms have a chief sustainability officer (CSO) to support the organizational focus on corporate social responsibility (CSR). Yet, there is much to learn about the boundary conditions that make the presence of CSOs particularly effective for firms’ CSR. Using an attention-based view lens, we investigate the relationship between having a CSO as attention carrier of CSR activities and examine the potential boundary conditions related to the three attention principles (attention selection, represented by board diversity; attention structures, represented (...) by a CSR committee; and situated attention, represented by country-level CSR standards). We test our hypotheses using a global sample of 3,470 firms across 54 countries. Our results show that the influence of the CSO on internal and external CSR is most important in the absence of attention principles that may act as alternative attention carriers of CSR. In other words, attention principles form boundaries to the CSO’s influence on internal and external CSR. Our study contributes to research on the attention-based view, CSOs, and CSR. (shrink)