The concept of cosmopolitanism makes transnational claims to a world citizenship that transcends national belonging. Istanbul, as the former Ottoman capital, is a city for which the practices and experiences of cosmopolitanism had meaning in a lived, local historic context. Istanbul’s elites had identities both local and foreign, and occupied blended cultural and political spaces. Today, Istanbul’s formerly Greek, Armenian, and Jewish neighborhoods are the subject of much nostalgia and investment. These areas also constitute a material reminder of the processes through which Istanbul was transformed from an Ottoman to a Turkish city and its non-Muslim minorities departed. I examine memories of Ottoman urbanism with a focus on how imaginations of the past are “made real” through ordinary neighborhood landscapes. Tensions embedded in Turkish cultural memory are the focus of much recent critical research. Scholars examine representations of national memory in museums, monuments, and architecture. The Ottoman past is preserved as historic, or it is erased, set apart both from the Turkish national imagination and from the lived spaces of everyday life. The local processes with which ordinary urban residents (not the state, municipality, or political representatives) imagine Istanbul’s Ottoman legacy through the landscape are less studied. In cultural media, Istanbul’s multicultural urban fabric embodies memories of a past where multilingual Istanbullus shared relationships with ethno-religiously diverse neighbors. The material landscape is being reshaped as former minority neighborhoods are gentrified, a situation which relies on the processes through which former minority properties were abandoned. I have been gathering diverse perspectives on these issues with externally funded ethnographic research in formerly multiethnic neighborhoods of Istanbul since 2001. While cosmopolitanism circulates in global political discourse as a normative ideal of tolerant pluralism, it also circulates in the global political economy to become a sign of elite identity. While representing Ottoman cosmopolitanism may respond to concerns for diversity, the process actually reproduces new forms of exclusion. Secondly, memories of the Ottoman past respond to an identity crisis. Istanbul is a city of migrants; memories of the Ottoman past play a role in the politics of defending or challenging what it means to be Istanbullu and Turkish. Finally, nostalgic representations of Istanbul’s cosmopolitan past obscure alternative memories of place. The urban cultural landscape does not merely represent, commemorate, or challenge memory, but is the means through which Istanbul residents perform national memory and thus reinterpret the cosmopolitan Ottoman legacy for the Turkish national present.