Organizations can be seen as amalgams of languages that can serve as a source of divisive tensions among employees. In our conceptual model, we draw upon social identity and social exclusion research to propose that linguistic diversity increases the potential for language-based exclusion in multilingual work settings. Language may cue listeners to ethnic or cultural stereotypes as well as negatively affect perceptions of speakers’ competence, leading listeners to exclude speakers of certain languages. We contend that when excluded, perception of oneself can be cast in an antagonistic relation to perceptions of others, with detrimental effects on prosocial behaviors. Perceptions of procedural unfairness, a weakened identity, and impaired mood serve to amplify the association between language-based exclusion and prosocial behaviors. However, organizational factors such as positive diversity climate may mitigate experiences with language-based exclusion. We outline an agenda for future research and discuss implications for human resource practice.