He is the son of Nouhad Diab and Wajdi Mallat, the first president of the Lebanese Constitutional Council (Arabic المجلس الدستوري) of Lebanon, from 1994 to 1997, and has three sisters, Manal, Raya and Janane. He is married to Nayla Chalhoub, and they have two adult sons, Tamer and Wajdi.