Recent historiography on late Ottoman port cities moves across two distinct currents of analysis. The first, a cultural-historical one, focuses on questions of urbanity and explores the impact of modernity on social space, the emergence of new social groups, interethnic coexistence and conflict, and eventually on the restructuring of communal and urban identities among those cities’ emerging middle-class strata. A second current explores the port cities from a socio-economic perspective as economic hubs integrating the Ottoman Empire as a periphery in the capitalist world economy. Despite their important contributions, these two currents rarely enter into dialogue with each other while both of them also seem to pay only scant attention to the principal historical agents, namely the merchants and entrepreneurs of the late Ottoman port cities. The proposed paper aims to bring these two currents together and offer a more systematic account of the historical experience of late Ottoman port-city merchants. Introducing the category of the ‘port merchant’, it will focus on the Jewish, Greek Orthodox, Ottoman Turkish, and Donme merchants of Salonica as shapers of the middle-class, interethnic, and civic character of the city’s elite. The establishment of a local chamber of commerce in 1882 provided the institutional framework for the coming together of a multi-ethnic group of prominent merchants delineating its boundaries anew. The paper will map their involvement in a broad web of weak and strong, open and close networks. It will be argued that the Chamber empowered the merchants in two ways. On the one hand, it provided a neutral space for the cultivation of internal links between them. These links were based on the shared notion of a common business and civic ‘interest’ that elevated the entrepreneur to the Salonican par excellence. On the other hand, the members of the Chamber benefited collectively from the external links each one of them individually contributed as part of numerous and overlapping associational, communal, municipal, business, and kinship networks. Institutions and/as networks thus facilitated group formation among the merchants of Salonica. At the same time though, they also determined this group’s internal hierarchies, placing the Donme rather than the Jews at the top and marginalizing the Greek Orthodox. The formation of a middle class identity in Salonica had therefore clear professional connotations and was in a constant interaction with the communal and civic identities concurrently being shaped.