This paper presents evidence of the interrelationships that existed between the Royal Society in its early years, the slave colonies, and the West African slave trade, first under the auspices of the Royal Adventurers, and later the Royal African Company (RAC). First, it examines the extent of the overlapping of memberships between the bodies. Second, it chronicles the Society's ownership of shares in the RAC. Third, it investigates involvement by Fellows of the Society in the administration of the (then) slave colony of Jamaica. Finally, it presents a few relevant extracts from the Society's foreign correspondence from outposts of the rising empire, and also extracts from discussions at ordinary meetings concerning the cause of the differences in colour between Europeans and Africans. Following the sale of its shares in the RAC in 1699, no further investments in the slave trade by the Society are known to have occurred.