After winning the Miss Flandre title in Bailleul, Mittenaere entered the Miss Nord-Pas-de-Calais 2015 pageant in Orchies, which she won. Mittenaere represented Nord-Pas-de-Calais at the Miss France 2016 pageant. On 19 December 2015, she was crowned Miss France by Miss France 2015 Camille Cerf in Lille.