This article presents a comprehensive analysis of the situation of migrant children in the educational system of Saint Petersburg. The authors review the evolution of research on child migration, beginning in the 1970s when this topic first drew the attention of European researchers, and trace its growing relevance in the Russian context from the 2010s to the present. Particular attention is paid to schools with a high proportion of immigrant students. The study offers a detailed examination of the factors contributing to the emergence of such schools, including migration flows, urban infrastructure characteristics, and institutional mechanisms of student distribution.