The victim, Rojhat Ozdel, was killed by a bullet while anti-riot police responded to stone-throwing protesters at the rally in the city of Yuksekova, according to witnesses.
Local authorities said that the young protester was "implicated in the violence against police forces".
An autopsy will be carried out to determine the cause of his death.
Another protester was wounded in the clashes.
The protest rally had been called to commemorate the death of three demonstrators in the same city in a confrontation with police a year ago.
The protesters were demonstrating against Ankara's refusal to intervene militarily to help the Kurds defend the Syrian border city of Kobane which has been under siege by jihadists from the Islamic State group.