Despite all the discussion of the rise of nationalism and populism over the last 15 years, the relationship between nationalism and immigration is curiously understudied. In this Introduction to Migration and Nationalism: Theoretical and Empirical Perspectives, we first conceptualize nationalism as (1) a set of (trans)-territorial, exclusionary, and anti-immigrant state discourses, policies, and practices that cover the whole national territory, or that are sub-territorial; (2) as a set of discourses (and violent) practices of (unelected) radical right wing political parties; and as a set of discourses against certain forms of more expansive immigration (policies) as manifested in both on-line and off-line civil society movements. We then ask whether nationalism has in fact increased over approximately the last 15 years in the wake of antagonism toward ‘neoliberalism,’ as proposed by some scholars. Lastly, we examine the consequences of (sub-state) nationalisms for immigration in especially, but not exclusively, Europe and North America.