Language is an important social category that is used to divide the social world. Starting early in life, children can distinguish familiar and unfamiliar languages and start to choose friends and informants based on language. However, little is known about how children’s exposure to different language speakers from their social environment influences their social preferences and learning decisions. The current study examined how linguistic diversity within children’s social networks and neighborhoods relate to children’s perception of familiar and unfamiliar language speakers. Eighty-seven 6-year-old U.S. children’s neighborhood and social network were assessed as they made judgments about how much they liked unfamiliar language speakers (i.e., Korean speakers) and familiar language speakers (i.e., English speakers) and how knowledgeable they found these speakers. Overall, children were found to selectively favor speaks of a familiar language: They liked familiar language speakers more and considered familiar language speakers as more knowledgeable than unfamiliar language speakers. However, monolingual children exposed to greater linguistic diversity from their neighborhood were more likely to think unfamiliar speakers as knowledgeable. This finding suggests that for monolingual children, linguistic diversity in their neighborhood may play a crucial role in shaping how they think about the knowledge state of unfamiliar language speakers. This study shed lights on how children’s language-based social and learning preferences are shaped by their linguistic environment.