Junot Díaz was born on December 31, 1968 in Santo Domingo, Dominican Republic. He was the third child in a family of five. His parents were Rafael Antonio and Virtudes Díaz. Throughout most of his early childhood, he lived with his mother and grandparents while his father worked in the United States.
When he was six years old, Junot Díaz immigrated with his family to Parlin, New Jersey, where he was re-united with his father. There he lived less than a mile from what he has described as "one of the largest landfills in New Jersey".