Fenati began racing minibikes in his early teens. In 2010, he made his debut in the Italian 125GP championship. He proved competitive and quickly moved up the ladder.
Fenati reached the Moto3 world championship in 2012 and confirmed his potential by finishing second at the season-opening race in Qatar and winning the Spanish GP at Jerez. He completed his first season sixth in the point standings.
In 2014, Fenati was hired by the Valentino Rossi-backed Sky Racing Team VR46 and finished third overall. Two years later, he clashed with team manager Uccio Salucci, Rossi's best friend, and lost his seat.
In 2017, Fenati had his best season to date, finishing second on a privately supported Honda. His potential was often obscured by his temper, both on the track and inside the team pit box.
Fenati moved up to Moto2 in 2018 with rather poor results. His winning potential was not forgotten, and in August MV Agusta announced Fenati would race the Triumph-powered MV Agusta-branded Forward Racing Moto2 entry in 2019.