Chain migration is a social process by which immigrants from a particular area follow others from that area to a particular destination, which may be in another country or in a new location within the same country. Chain migration occurs when individual members of a community migrate and then encourage or assist further movements of migration. In the United States, chain migration refers to the fact that U.S. immigration laws allow U.S. green card holders and residents the ability to sponsor family members from their home countries. The term "chain migration" has become contentious in the United States, with some advocates of limiting immigration using the term to partially explain the volume and national origins of legal immigration since 1965.

The process of chain migration is based on ethnic or family ties, with members of the same family migrating at different times, usually with primary wage earners migrating first, followed by secondary or non-wage earners. Family-based immigration has been a key component of U.S. immigration policy since the Immigration and Nationality Act (INA) was first enacted. However, some politicians, including former U.S. President Donald Trump, have criticized chain migration, arguing that it takes jobs and opportunities away from other, more qualified immigrants and United States citizens, and that it threatens national security.