This paper attempts to convey a sense of the increasing importance of the population question for the future of Canada and its social geographies. This future will be shaped as much by changes in population processes and living conditions as by economic and political factors. Specifically, four transformations are rippling through the country's social fabric and urban landscapes: slow growth and the demographic transition modifications to family forms and living arrangements; increasing ethnocultural diversity; and the shifting relationships among households, labour markets and the welfare state. There is increasing unevenness of population growth, juxtaposing localized growth and widespread decline, massive social changes, the concentration of immigration and new sources of diversity in metropolitan areas, and fundamental shifts in social attitudes concerning family, work and gender relations. Deepening contrasts in living environments and economic wellbeing flow from these trends, and the varied challenges they pose for private actors, governments and service-providers. Questions relating to the country's future population geographies and social structures are complex, analytically difficult, and politically charged, but are too important to ignore.