In this study, we investigated whether team-level knowledge sharing moderates the effects of individual-level expertise dissimilarity on individual employees’ creativity in research and development (R&D) project teams. Expertise dissimilarity—defined as the difference in expertise and knowledge between a focal team member and her or his fellow team members—was operationalized in terms of the research department to which each member belonged. In Study 1, multilevel analyses of data collected from 200 members of 40 R&D project teams in a telecommunications company revealed that a team member with expertise dissimilar to that of her or his teammates was more likely to exhibit creativity when the project team as a whole engaged in higher levels of tacit, rather than explicit, knowledge sharing. In contrast, a member whose expertise was similar to that of her or his teammates was more likely to exhibit creative behavior when the team engaged in higher levels of explicit, rather than tacit, knowledge sharing. These findings were largely replicated in Study 2 using data collected from 82 members of 25 project teams from another telecommunications company.