The Anatolia news agency says eight other relatives were injured during Sunday's celebration in the southeastern province of Gaziantep.
It says the groom lost control of the weapon and accidentally aimed at guests. He was arrested.
It is tradition in Turkey to shoot into the air to celebrate weddings, circumcisions or sports victories. Turkey has failed to curb the practice despite imposing harsher punishments to cut down on stray bullet accidents.
Police in Gaziantep were not available for comment.
