Fethullah Gulen has been accused of encouraging the coup attempt
The president points his finger towards Pennsylvania, home of exiled Fetullah Gulen, leader of the powerful Hizmet movement.
Turkey's president has accused a US-based Muslim preacher of being behind the attempted military coup against his government.
He promotes a philosophy which incorporates a mystical form of Islam with advocacy of democracy, education and science.
Mr Erdogan reacted by purging hundreds of army officers, including senior generals, shutting down schools operated by Hizmet and firing hundreds of police officers.
"As someone who suffered under multiple military coups during the past five decades, it is especially insulting to be accused of having any link to such an attempt. I categorically deny such accusations," he said in a statement.