This study examines changes in spatial distribution and residential segregation patterns of immigrant groups in South Korea from 2008 to 2021. Since the mid‐1990s, the immigrant community has increased rapidly; however, geographical stratification has intensified among heterogeneous immigrant groups. Foreign immigrants from 195 countries are divided into four groups based on the average income in the country of birth. Dissimilarity and multigroup entropy indices were adopted to explore the aspatial aspects of immigrant segregation. Exploratory spatial data analysis was used to examine the spatial separation of foreign clusters. The implications of these results are threefold. First, immigrant residential segregation is as serious as in developed countries and has deepened. Second, immigrants from advanced economies are concentrated in Seoul, while immigrants from upper‐middle economies are clustered in the southwestern part of the capital region. In contrast, immigrants born in lower‐middle class and underdeveloped countries are distributed among rural and manufacturing areas in the non‐capital region. Finally, the differences in the course of economic migration according to socioeconomic background are considered to be the decisive cause of the spatial segregation of immigrants. This study challenges policymakers engaged in integrating immigrant communities in South Korea.