The Holy Innocents' Cemetery is a defunct cemetery in Paris that was used from the Middle Ages until the late 18th century. It was the oldest and largest cemetery in Paris and had often been used for mass graves. It was closed because of overuse in 1780, and in 1786 the remaining corpses were exhumed and transported to the unused subterranean quarries near Montparnasse known as the Catacombs. The place Joachim-du-Bellay in the Les Halles district now covers the site of the cemetery.

A mass grave is a grave containing multiple human corpses, which may or may not be identified prior to burial. The United Nations has defined a criminal mass grave as a burial site containing three or more victims of execution, although an exact definition is not unanimously agreed upon. Mass graves are usually created after many people die or are killed, and there is a desire to bury the corpses quickly for sanitation concerns. Although mass graves can be used during major conflicts such as war and crime, in modern times they may be used after a famine, epidemic, or natural disaster. In disasters, mass graves are used for infection and disease control. In such cases, there is often a breakdown of the social infrastructure that would enable proper identification and disposal of individual bodies.