Purpose: This study aims to investigate how job self-efficacy mediates the relationship between online knowledge sharing and employee innovation. To fully understand this relationship, this study also tests the moderating role of an innovative climate. Design/methodology/approach: This study gathered data from 353 full-time employees working at information technology companies in Vietnam. This study used structural equation modeling to test hypotheses. Findings: The results showed that online knowledge sharing positively influenced employee innovation directly and indirectly through job self-efficacy. Moreover, innovative climate positively affected employee innovation as well as moderated the nexus between online knowledge sharing and employee innovation. Originality/value: First, this study provides further evidence that job self-efficacy plays a mediator linking online knowledge sharing with employee innovation. Second, this paper confirms that an innovative climate can play a mixed moderator that not only influences employee innovation but also moderates the association between online knowledge sharing and employee innovation.