Slavery is the ownership of a person as property, especially in regards to their labour. Slavery typically involves compulsory work, with the slave's location of work and residence dictated by the party that holds them in bondage. Enslavement is the placement of a person into slavery, and the person is called a slave or an enslaved person (see § Terminology).

Many historical cases of enslavement occurred as a result of breaking the law, becoming indebted, suffering a military defeat, or exploitation for cheaper labor; other forms of slavery were instituted along demographic lines such as race or sex. Slaves would be kept in bondage for life, or for a fixed period of time after which they would be granted freedom. Although slavery is usually involuntary and involves coercion, there are also cases where people voluntarily enter into slavery to pay a debt or earn money due to poverty. In the course of human history, slavery was a typical feature of civilization, and existed in most societies throughout history, but it is now outlawed in most countries of the world, except as a punishment for a crime. In general there were two types of slavery throughout human history: domestic and productive.

In chattel slavery, the slave is legally rendered the personal property (chattel) of the slave owner. In economics, the term de facto slavery describes the conditions of unfree labour and forced labour that most slaves endure. In 2019, approximately 40 million people, of whom 26% were children, were still enslaved throughout the world despite slavery being illegal.