ABSTRACT: In this article, we argue for understanding immigrant suburbanization as one outcome of the mass migrations associated with economic globalization, a process that has coincided with and shaped the decentralization and reconfiguration of the American metropolis. We contend, as well, that economic differentiation among the foreign-born translates into distinctive residential patterns that reflect the diversity of new metropolitan geographies. Using individual and tract-level data from metropolitan Philadelphia since 1970, we describe the intersection of spatial differentiation (suburban variety) with both demographic diversity (ethnic and racial differentiation) and linked patterns of ethnic and racial population growth and decline. We highlight the importance of immigration to population and economic growth, the diversity among immigrants, the inability of “suburb” to capture the region's residential ecology, and the surprising links between the growth of immigrant and African-American populations in the same places. We clearly show how the residential experience of African Americans differs from that of both immigrants and native-born whites.