"Our intelligence organizations confirm his death," Fidan told a press conference.
Earlier in the day, media reported that Gulen who was accused of attempting a coup in 2016, has died in the United States.
A CNN Turk correspondent, Hande Firat, reported later in the day that the preliminary cause of Gulen's death is kidney disease, which he suffered from for many years.
The Turkish government accused Gulen of being responsible for a coup attempt in 2016.
Gülen, who had been living in self-imposed exile in the United States since 1999, rejected the accusations and condemned the attempted coup.