Large-scale mining projects transform social landscapes as much as they do natural ones. This is particularly the case in contexts such as Melanesia, where much of the land is held under forms of customary tenure. Drawing on a conceptual model developed by Nicholas A. Bainton and Glenn Banks that links mine-induced migration with social change and identity transformations, this chapter examines in-migration issues at case studies of two advanced exploration projects and two long-established large-scale mining operations in Papua New Guinea. This allows the authors to refine the conceptual model, emphasizing the ways in which particular forms of kinship organization, specific geographies, and regional migration histories are critical factors that shape the nature and extent of mine-induced migration, as well as potential community and corporate responses to it.