Sociolinguistics are of paramount importance in heritage language (HL) education because the macro-sociolinguistic context shapes HL speakers’ language experiences, knowledge, and use, as well as their socioaffective relationship to the language. This chapter offers a historical overview of sociolinguistic research, as well as a discussion of current concerns, including: the sociolinguistic characteristics of HL speakers; macro-sociolinguistic issues such as societal language ideologies and policies, and HL identities; and sociolinguistic research in educational contexts. In addition, we examine the place of sociolinguistics in HL curricula and we offer specific recommendations for HL educators. We conclude by identifying areas for future research.