This paper is concerned with an examination of some aspects of the emergence of functional and social segregation in Cork over the period 1787 to 1863. The discussion is placed in the context of the general conclusions reached by some geographers who have carried out research on this topic in recent years. The central question which has emerged from such work has been to what extent well-defined levels of differentiation emerged in the nineteenth century city and to what did they owe their development. Here, the development of differentiation in Cork is examined through a study, based on information available in street and trade directories, of some activities which were sensitive to social and economic change and whose location may therefore reveal aspects of such differentiation. It emerges from the study that the city exhibited clear but spatially limited segregation in the late eighteenth century and that it was not until the mid-nineteenth century that the well-defined differentiation which characterises the modern city became evident.