Lee was born in Seoul, South Korea. Her family came to the United States in 1976, when she was seven years old, and she grew up in Elmhurst, Queens, New York. Her parents owned a wholesale jewelry store there. As a new immigrant, she spent much time at Queen's library, where she learned to read and write. She attended the Bronx High School of Science, and later studied history at Yale College in Trumbull College and law at Georgetown University Law Center. She also worked as a corporate lawyer in New York for several years before becoming a writer. She lived in Japan for four years from 2007 to 2011. Lee lives in New York with her son, Sam, and her husband, Christopher Duffy, who is half Japanese.