Regional science came of age in the post-World War II era, when rapid advances were being made in many fields of science and computational technologies were blossoming; large-scale urban and regional modeling and normative approaches to planning were in vogue. The multidisciplinary field has perhaps been most closely associated with its methods. But the topics of regional science research have also reflected conditions extant in a world undergoing a profound demographic transformation. The most developed countries have now completed their long-term fertility transitions, and most of the still-developing countries have now moved out of the early expanding stage. At a regional and local scale, settlement patterns in much of the developed world have been characterized by urban sprawl and suburbanization, as well as periodic counter-urbanization starting the 1970s, while in the developing world rapid urbanization has been the norm with the growth of many new mega-cities. These trends all reflect the changing age composition attendant to demographic transition. In this chapter, we attempt to lay out some of the changing needs and issues for regional research as world population growth slows, as labor forces age in both more developed and rapidly developing countries, as advances in gender equality proceed apace, and when, in many regions, little population change or even population losses become as likely as continued population growth. We offer some provocative thoughts on nine broad topics where we think looking through the lens of demographic aging can help scope out policy concerns and research needs for the future.