We highlight the social aspects of team creativity by proposing that team creativity is influenced by two types of team social capital: bridging and bonding social capital. Going beyond the structural perspective, we posit that team-level human capital diversity is one of the potential antecedents of social capital for team creativity. We suggest that network structures are formed by teammates' interactions, which are largely the result of differences in their individual characteristics. The results of an empirical study using 36 teams of MBA students showed that the interaction of team-bridging social capital with team-bonding social capital was positively and significantly related to team creativity. Knowledge variety and knowledge disparity had a joint effect on team-bridging social capital, and knowledge separation was negatively related to team-bonding social capital. Moreover, team social capital mediated the effects of knowledge diversity on team creativity. Our study has several important implications for team creativity, social networks, and diversity research.