Gozde Kurt, a 16-year-old student at the rally in Istanbul, said: "Just a small group from Turkish armed forces stood up against our government ... but we, the Turkish nation, stand together and repulse it back."
The Yeni Safak newspaper used the headline "Traitors of the country," while the Hurriyet newspaper declared "Democracy's victory."
Prime Minister Binali Yildirim said the perpetrators of Friday's failed coup "will receive every punishment they deserve".
However, the government crackdowns raised concerns over the future of democracy in Turkey, which has long prided itself on its democratic and secular traditions despite being in a region swept by conflict and extremism.