Sununu was born in Havana, Cuba while his parents were visiting Cuba on a business trip. He is the son of John Saleh Sununu, an international film distributor, and Victoria Sununu (née Dada). His father's family came to the US from Lebanon at the turn of the 20th century. His father's ancestry is Lebanese and Palestinian from the Greek Orthodox Church community in Jerusalem and Beirut. John Saleh Sununu was born in Boston, Massachusetts. His mother Victoria Dada was born in El Salvador. Her family was a Greek Orthodox Christian family from Lebanon that settled in Central America at the turn of the 20th century. Sununu visited Beirut, Lebanon as a child in the late 1940s. He grew up in New York City and graduated from the La Salle Military Academy on Long Island.