Research on first language, second language, and multilingual socialization has flourished over the past three decades in many formal and informal educational contexts around the world. One relatively recent site for such research, particularly for multilingual students learning English as an additional language, is post-secondary institutions where English is the medium of instruction. This article reviews research on this topic conducted at Canadian universities in particular, focusing both on students enrolled in short (one year or less) study-abroad programs and on those in full degree programs (undergraduate and graduate) whose goals may include improving their English language proficiency and their disciplinary knowledge in various fields. It highlights the changing theoretical understandings of language/literacy socialization processes based on a number of studies, in terms of students' trajectories, the interplay of students' (multiple) languages in their learning and performance, the various agents and directions of their socialization, acts of resistance versus compliance with established norms, and the role of peer support and social networks in their academic and social experiences, and ways of tracking these. In addition, the article notes the various methodological approaches that exist for studying issues related to language/literacy socialization and the units of analysis typically involved in this research.