As a result, 34 children are now among those killed in the suicide attack in the city of Gaziantep which President Recep Tayyip Erdogan said was carried out by a child bomber acting on the orders of the Islamic State group.
Mahsun Nas, 13, was the latest victim of the bombing on August 20, the Dogan news agency reported, and succumbed to his injuries while in hospital where he had been since the attack.
The bombing was the deadliest in 2016 after the country has suffered more than a year of attacks linked to IS and Kurdish militants.
A triple suicide bombing and gun attack at Istanbul's Ataturk airport in June left 47 dead, with authorities pointing the finger at the extremist group.
Four days after the attack, Ankara launched its unprecedented military incursion into northern Syria against IS militants and Syrian Kurdish rebels linked to the outlawed Kurdistan Workers' Party (PKK) waging an insurgency in southeastern Turkey.