This special issue addresses the concealment of slavery and other forms of coerced labour. It brings together contributions from scholars working on different regions and time periods between the eighteenth and early twentieth centuries. The starting point is the observation that in the wake of abolitionism and imperial anti-slavery rhetoric, persisting areas of slavery and coerced labour became increasingly hidden. The term “hidden economies” helps to identify those areas that have been (and often still are) less visible for a variety of reasons, be it the development of shadow economies around them, the opacity of increasingly complex global supply chains, the remoteness of the region concerned, or the marginalisation of the economic sectors involved.