His parents, Anna Rachel and Judah Asimov, were Jews.
Isaac Asimov was born in Petrovichi, Russia (near Smolensk) in 1920, around 2 January. He was the son of Judah Asimov and Anna Asimov who immigrated to the United States in Brooklyn, New York when Isaac was three where they owned a series of candy stores. Although his parents, Anna Rachel and Judah Asimov, were Jews, they did not raise the young Isaac to be religious. As a youngster, growing up in Brooklyn, New York, Asimov soon showed himself to be remarkably bright, with an extraordinary memory. By the time he was five he had taught himself to read. And despite the family's frequent moves (selling one candy store in order to buy another in a new location), he was always at the head of his class, and frequently being promoted. He skipped half of kindergarten, half a year of first grade, and half a year of third grade. Being quick to perceive the lesson before the teacher had gotten more than part way through it, he often became bored in class.
At the same time he was socially and physically awkward. He never learned how to ride a bike or swim, and if he spent even ten minutes out in the sun his skin would burn fiercely. He was also a claustrophiliac, having a peculiar liking for small, enclosed spaces. At age nine he began working in the family store where he discovered science fiction novels, by eleven he had begun his first novel.