The East African coast has long been recognized as a cosmopolitan region, where different cultures and peoples met and exchanged ideas, goods and knowledge. The culture that developed there from the seventh century ce was shaped by these relations, often referred to under the term Swahili, and many of the coastal residents engaged in Islamic practice, long-distance trade, conspicuous consumption of valued goods, and spoke a common language. This paper investigates the presence of slaves and migrants from the East African interior, through pottery assemblages uncovered at two eleventh- to fifteenth-century ce sites in northern Zanzibar: Tumbatu and Mkokotoni. These are groups of people not usually discussed in relation to medieval Swahili towns, and slavery has been especially difficult to study archaeologically on the coast. Through a material culture of difference, I argue that enslaved and non-elite migrants can be recognized and allow for a fuller understanding of socio-economic and cultural complexity in Swahili towns.