Slavery has historically been widespread in Africa. Systems of servitude and slavery were once commonplace in parts of Africa, as they were in much of the rest of the ancient and medieval world. When the trans-Saharan slave trade, Red Sea slave trade, Indian Ocean slave trade and Atlantic slave trade (which started in the 16th century) began, many of the pre-existing local African slave systems began supplying captives for slave markets outside Africa. Slavery in contemporary Africa still exists in some regions despite being illegal.

In the relevant literature, African slavery is categorized into indigenous slavery and export slavery, depending on whether or not slaves were traded beyond the continent. Slavery in historical Africa was practiced in many different forms: Debt slavery, enslavement of war captives, military slavery, slavery for prostitution and enslavement of criminals were all practiced in various parts of Africa. Slavery for domestic and court purposes was widespread throughout Africa. Plantation slavery also occurred, primarily on the eastern coast of Africa and in parts of West Africa. The importance of domestic plantation slavery increased during the 19th century. Due to the abolition of the Atlantic slave trade, many African states that were dependent on the international slave trade reoriented their economies towards legitimate commerce worked by slave labour.

Different forms of slavery and servitude existed throughout African history and were shaped by indigenous practices of slavery as well as the Roman institution of slavery (and the later Christian views on slavery), the Islamic institutions of slavery via the Muslim slave trade, and eventually the Atlantic slave trade. Slavery was part of the economic structure of African societies for many centuries, although the extent varied. Ibn Battuta, who visited the ancient kingdom of Mali in the mid-14th century recounts that the local inhabitants competed with each other in the number of slaves and servants they had and was himself given a slave boy as a "hospitality gift." In sub-Saharan Africa, the slave relationships were often complex, with rights and freedoms denied individuals held in slavery and restrictions on sale and treatment by their masters. Many communities had hierarchies between different types of slaves: for example, differentiating between those who had been born into slavery and those who had been captured through war.

"The slaves in Africa, I suppose, are nearly in the proportion of three to one to the freemen. They claim no reward for their services except food and clothing, and are treated with kindness or severity, according to the good or bad disposition of their masters. Custom, however, has established certain rules with regard to the treatment of slaves, which it is thought dishonourable to violate. Thus the domestic slaves, or such as are born in a man's own house, are treated with more lenity than those which are purchased with money. ... But these restrictions on the power of the master extend not to the care of prisoners taken in war, nor to that of slaves purchased with money. All these unfortunate beings are considered as strangers and foreigners, who have no right to the protection of the law, and may be treated with severity, or sold to a stranger, according to the pleasure of their owners."

The forms of slavery in Africa were closely related to kinship structures. In many African communities, where land could not be owned, enslavement of individuals was used as a means to increase the influence a person had and expand connections. This made slaves a permanent part of a master's lineage and the children of slaves could become closely connected with the larger family ties. Children of slaves born into families could be integrated into the master's kinship group and rise to prominent positions within society, even to the level of chief in some instances. However, stigma often remained and there could be strict separations between slave members of a kinship group and those related to the master.

Chattel slavery is a specific servitude relationship where the slave is treated as the property of the owner. As such, the owner is free to sell, trade, or treat the slave as he would other pieces of property, and the children of the slave often are retained as the property of the master. There is evidence of long histories of chattel slavery in the Nile River valley, much of the Sahel and North Africa. Evidence is incomplete about the extent and practices of chattel slavery throughout much of the rest of the continent prior to written records by Arab or European traders.

Many slave relationships in Africa revolved around domestic slavery. Slaves would work primarily in the house of the master but retain some freedoms. Domestic slaves could be considered part of the master's household and would not be sold to others without extreme cause. The slaves could own the profits from their labour (whether in land or in products) and could marry and pass the land on to their children in many cases.

Pawnship, or debt bondage slavery, involves the use of people as collateral to secure the repayment of debt. Slave labour is performed by the debtor or a relative of the debtor (usually a child). Pawnship was a common form of collateral in West Africa. It involved the pledge of a person or a member of that person's family, to serve another person providing credit. Pawnship was related to, yet distinct from, slavery in most conceptualizations, because the arrangement could include limited specific terms of service to be provided, and because kinship ties would protect the person from being sold into slavery. Pawnship was a common practice throughout West Africa prior to European contact, including among the Akan people, the Ewe people, the Ga people, the Yoruba people, and the Edo people (in modified forms, it also existed among the Efik people, the Igbo people, the Ijaw people, and the Fon people).