The aim of the study is to test not only the relative importance effect of employees' external and internal corporate social responsibility (CSR) perceptions on prosocial and proactive behaviors (i.e., organizational citizenship behavior OCB and job crafting) but also the impact of the interaction of these two kinds of employee CSR perceptions on proactive behaviors. Survey‐based data were collected from 181 employees at eight luxury hotels located in South Korea. Using a two‐wave longitudinal design, we measured employees' internal and external CSR perceptions, and then their supervisors rated OCB and job crafting one month after. Hierarchical moderated regression model is employed to test research hypotheses. The results showed that employees' internal CSR perceptions are more strongly related to prosocial and proactive behaviors than employees' external CSR perceptions are. Furthermore, the positive relationship between internal CSR perceptions and prosocial and proactive behaviors was more pronounced when external CSR perceptions were high than when they were low. The theoretical and managerial implications of the results and the limitations of the study are discussed, and future research directions are suggested.