Amr al-Azm told AP via Skype on Monday that his father died the night before in Berlin, two months after his health sharply deteriorated.
Al-Azm, who lectured at several universities around the world and held a PhD from Yale in Modern European Philosophy, left Syria a year before the country's crisis began in March 2011. He was a critic of the government.
Al-Azm's most famous book was "The Critique of Religious Thought" that led to him being sued for denigrating Islam.
He is survived by his wife, Iman Shaker and two sons, Amr and Ivan.