Charles Julien Isidore de Stein d'Altenstein (1819–1896) was a civil servant in the Belgian ministry of foreign affairs, with a particular interest in heraldry and genealogy. He was born in Mesnil-Saint-Blaise (Houyet), the second son of Charles Frédéric Guillaume, baron Stein d'Altenstein and Marie-Catherine de Malmédy de Deignée. His father's family was originally from Germany. He married Justine Lysen (1827–1860), with whom he had three children, Julien, Armand and Clotilde.