The 9 September massacres were two series of massacres of prisoners at Versailles on 9 September 1792 during the French Revolution. They occurred in the context of the September Massacres. Claude Fournier was accused of complicity in them. Those killed included Charles d'Abancourt, Claude Antoine de Valdec de Lessart and Louis Hercule Timoléon de Cossé-Brissac.
The following evening, the assassins returned to the écuries de la Reine, now known as the prison of Versailles, to carry out a second massacre of 30 inmates.