This article reviews recent research on the roles of formulaic language in language socialization theory and research from the point of view that formulaic language is a chunk of language (e.g., one word, string of several words) repeatedly used in verbal routines and other contexts. Although the notion of formulaic language is not always explicitly discussed in the literature of language socialization, previous research suggests that formulaic language is indeed an important notion within the theory of language socialization, for it often plays a crucial role in socializing novices to social dimensions such as politeness, hierarchy, and social identities including social roles and statuses, and relationships. This article first provides a brief introduction of language socialization theory, its research methods, and recent developments. It then reviews recent language socialization research on formulaic language in first and second language (L1, L2) and heritage language environments, including how novices are socialized to use formulaic language, how they are socialized through its use, and how they actually use it in normative and novel ways in participating in social interaction with experts and/or peers. Finally, the major findings of recent studies are summarized, and the article concludes by suggesting several directions for further research on formulaic language in language socialization.