Althusser was born in French Algeria in the town of Birmendreïs, near Algiers, to a pieds-noirs family.^[2] He was named after his paternal uncle who had been killed in the First World War. Althusser alleged that his mother had intended to marry his uncle, and married his father only because of the brother's death. Althusser later alleged that his mother treated him as a substitute for his deceased uncle, to which he attributed deep psychological damage.

Following the death of his father, Althusser moved from Algiers with his mother and younger sister toMarseille, where he spent the rest of his childhood. He joined the Roman Catholic youth movement Jeunesse Étudiante Chrétienne in 1937.^[2] Althusser was a brilliant student at the Lycée du Parc in Lyon and was later accepted by the elite École Normale Supérieure (ENS) in Paris.^[2] However, he was drafted in the run-up toWorld War II and, like most French soldiers following the Fall of France, Althusser was interned in a Germanprisoner of war camp. Here, he began the thinking that took him toward Communism. He was held in the camp for the rest of the war, under conditions that contributed to his lifelong bouts of mental instability.^[2]