This paper seeks to challenge the notion of the invisible slave in the archaeological record and investigates the way in which material culture may reflect the movements and practices of enslaved labourers on the East African Swahili coast. Archaeological approaches to enslavement have revealed the nuanced and complex experiences of a group of people often under-represented or absent in historical records, while also grappling with the challenges presented by the ambiguity of the material evidence. This paper presents a case study from the fifteenth-century Swahili site of Songo Mnara in Tanzania, an architecturally and materially wealthy stone town in the Kilwa archipelago. It focuses on the context, use, and spread of beads across the site, and considers the possibility of interpreting some classes — such as locally made terracotta beads — as proxies for the underclass and enslaved in an otherwise wealthy settlement. It presents a key study towards the aim of building a highly necessary methodology for the archaeology of slavery in East Africa and beyond, and suggests that certain types of material culture might be used to explore the activities of enslaved and/or underclass individuals.