Qanawātī was born in Alexandria on June 6, 1905 to a Greek Orthodox Christian family. He later converted to Catholicism. He obtained his degree in pharmacology from the Saint Joseph Jesuit College in Beirut in 1926, a diploma in chemical engineering from Lion university in France in 1928. In 1934, Qanawātī joined the Dominican monasticism in Paris, where he started his research journey and studied philosophy and theology. He collected a large number of Islamic books.