This chapter reviews the major theoretical approaches to international migration and considers their use as a tool to explain the dynamics surrounding the migration processes, meanings of citizenship, race/ethnicity, racism, stigmatization, and other challenges that undocumented youth encounter in interacting with institutions, particularly in their pursuit of a tertiary-level education. It argues that undocumented students—or undocumented youth more generally—may not necessarily fit the parameters that these models of international migration suggest, given that most of them arrived as children when the decision was not theirs. However, these models serve as explanatory tools to improve the understanding of the circumstances that motivate parents to migrate with children but without the legal status that would afford them the opportunity to live full, free lives without fear of deportation and with access to education, employment, and other basic privileges such as driving and travelling.