Hostin was born on October 20, 1968, in New York City to a Puerto Rican mother, Rosa Beza, and an American father, William Cummings. Her maternal grandfather was a Sephardic Jew. On the PBS program Finding Your Roots, Hostin learned that she has a large amount of Spanish ancestry and that she is a descendant of Spanish colonizers, with her fourth great-grandfather being a trader of slaves. Hostin was raised in The Bronx, New York City, attended the all-girls Dominican Academy