This year's race for the Goncourt was dominated by books about the West's love-hate relationship with Islam and the Arab world.
Though Enard's Boussole, or Compass in English, had been the critics' favourite for the award, some had speculated that Franco-Tunisian author Hedi Kaddour might win, as the jury had chosen to announce its final four selections in Kaddour's birthplace, Tunis.
Writers Nathalie Azoulai and Tobie Nathan had also made the shortlist. The jury is said to have chosen the winner on Tuesday over lunch at restaurant in Paris.
Having already won the booksellers' prize for Compass, Enard, 43, says he is "extraordinarily happy" over now winning the Goncourt.
Although the Goncourt is the oldest and most prestigious literary prize in the French-speaking world, it comes with only 10 euros in prize money. It is nevertheless objectively worth much more, because it always sends its winner to the top of the year's bestselling lists, which significantly boosts book sales.