Human sacrifice is the act of killing one or more humans as part of a ritual, which is usually intended to please or appease gods, a human ruler, public or jurisdictional demands for justice by capital punishment, an authoritative/priestly figure or spirits of dead ancestors or as a retainer sacrifice, wherein a monarch's servants are killed in order for them to continue to serve their master in the next life. Closely related practices found in some tribal societies are cannibalism and headhunting.

Human sacrifice was practiced in many human societies beginning in prehistoric times. By the Iron Age (1st millennium BCE), with the associated developments in religion (the Axial Age), human sacrifice was becoming less common throughout Africa, Europe, and Asia, and came to be looked down upon as barbaric during classical antiquity. In the Americas, however, human sacrifice continued to be practiced, by some, to varying degrees until the European colonization of the Americas. Today, human sacrifice has become extremely rare.

Modern secular laws treat human sacrifices as tantamount to murder, even in countries with a higher degree of religious freedom. Most major religions in the modern day condemn the practice. For example, the Hebrew Bible prohibits murder and human sacrifice to Moloch.