The unanimous decision by the Federal Supreme Court means Ali Sipahi can remain in the Latin American country where he has lived for the past 12 years.
Sipahi faced charges in Turkey of belonging to a terrorist organisation involved in the failed coup against Turkish President Recep Tayyip Erdogan in July 2016.
The dual Turkish and Brazilian citizen had initially been held in jail, but was freed in May as he awaited the court's decision.
Sipahi, who owns a restaurant in Sao Paulo and is married and has a child, is involved in the Brazil-Turkey Cultural Center and Turkey-Brazil Chamber of Commerce and Industry, which are connected to Gulen's "Hizmet" (Service) movement.
He had been targeted for depositing money in Turkish bank Asya, which has been linked to Gulen, his lawyer said previously.
Gulen, who lives in self-exile in the United States, is accused of ordering the attempted overthrow of Erdogan, but he strongly denies any involvement.
Ankara calls Gulen's Hizmet movement a terrorist group, but followers insist they are part of a peaceful organisation promoting moderate Islam and education.
Tens of thousands of people have been arrested by Turkey in the crackdown that followed the attempted putsch and the Turkish authorities have also brought back suspects in secret operations from foreign countries including Ukraine and Kosovo.
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