Born to a Protestant family in Beirut, Salibi's family came from the Lebanese village of Bhamdoun in French Mandatory Lebanon. After studying at French missionary schools in Bhamdoun and Broummana, he completed his secondary education at the Prep School in Beirut (now International College), and his BA in History and Political Science from AUB, before moving to the School of Oriental and African Studies, SOAS (University of London) where he earned his PhD in history in 1953 under the supervision of historian Bernard Lewis. His dissertation was subsequently published under the title "Maronite Historians of Mediaeval Lebanon".