Nicolò Zaniolo was born on 2 July 1999 in Massa, Italy. He is the son of Igor Zaniolo, a former professional footballer who played as a forward in Serie B and Serie C. Zaniolo grew up in the Fiorentina youth system. On the final day of the 2016 mid year transfer window, he was released by Fiorentina, and subsequently joined Virtus Entella. After several months playing for the Entella Primavera side, Zaniolo was given his professional debut in Serie B on 11 March 2017, aged 17, in a 3–2 win against Benevento. On 5 July 2017, Internazionale announced they had signed Zaniolo, for a reported fee of €1.8 million, plus €1.7 million in bonuses. He played for the Primavera side in the 2017–18 season, but didn't play any competitive game for Inter's first team. In June 2018, it was reported that Zaniolo and Davide Santon had joined Roma as a part of the deal moving Radja Nainggolan to Inter. He signed a five-year contract with the club, for a fee of €4.5 million plus 15% resell revenue.