Seydoux's parents are both partly of Alsatian descent. Her father is a great-grandson of businessman and inventor Marcel Schlumberger, while her mother is a granddaughter of Marcel's brother, Maurice Schlumberger. The family name came to exist in 1902, when Seydoux's great-great-grandfather Charles-Louis-Auguste-Jacques Seydoux (1870–1929) married Mathilde, daughter of Languedoc aristocrat François Fornier de Clausonne de Lédenon, whose family held the titles of Baron de Lédenon and seigneur de Clausonne, de Laugnac et de la Bastide d'Albe. The Seydoux family is widely known in France. Her grandfather, Jérôme Seydoux, is the chairman of Pathé; her granduncle, Nicolas Seydoux, is the chairman of Gaumont Film Company; her other granduncle, Michel Seydoux, also a cinema producer, is the chairman of the Lille-based football club Lille OSC; and her father is CEO of the French wireless company Parrot. Despite Seydoux's connections, her family initially took no interest in her film career and did not help her. As a child, she had no desire to act. She instead wanted to be an opera singer, studying music at the Conservatoire de Paris.