Marie-Madeleine Postel, born Julie Françoise-Catherine Postel, was a French Catholic professed religious and the founder of the Sisters of Christian Schools. Postel was also a member from the Third Order of Saint Francis and had served as a schoolteacher after the French Revolution where she oversaw the education of around 300 children. The Revolution saw her use her then-disbanded school to house fugitive priests despite the great risk that posed to her own life.