The death raises the toll from the attacks on 15 March to 51.
Turkey's Foreign Minister Mevlut Cavusoglu said on Twitter the man who was "critically wounded in the treacherous attack in Christchurch" had died.
Police said in a statement they were informed late last night that a man injured in the Al Noor Mosque on 15 March had died.
The 46-year-old had been in a critical condition in Christchurch Hospital since the terror attack.
