In the sixteenth century, the Republic of Venice witnessed the unprecedented diffusion of Pro Amore Dei dwellings—a novel form of tenure that offered dwellings free of charge or at very low rents to those in need. This innovative practice gave rise to the construction of several purpose-built, large-scale, collective row-housing blocks designed to accommodate specific groups of urban poor. Through a close reading of two case studies, namely Corte San Rocco and Corte San Marco, this essay argues that the Venetian Pro Amore Dei housing case may be read as an architectural, bureaucratic, and ideological precursor to modern social housing models. Aspects such as the development of collective row housing blocks, the financial mechanisms that sustained their construction, maintenance and lease, their efficient circulation systems, the repeated and standardized floor plans of the dwellings, the overall economization of construction, and most importantly, the typological and aesthetic qualities of these housing blocks prefigure many of the defining characteristics of modern social housing. Indeed, although social housing first emerged only in the twentieth century, the Venetian experience examined in this essay allows us to shed light on some of the inherent contradictions, complexities, and tensions that have marked the longue-durée prehistory of this phenomenon.