Former Spanish Grand Prix motorcycle rider. He is the nephew of the legendary motorcycle champion Angel Nieto and began competing in the motor world in 1994. After the success in the 250cc class, he changed to World Superbikes and started in MotoGP. In 2010 he returned to the Grand Prix scene in the newly formed Moto2 category, but Nieto announced his retirement from the competition in the beginnings of 2011 after not being able to recover from the injuries suffered by competing in Indianapolis in 2010.

In the same year he started in the world of fashion as an influencer. A year later, after leaving the competition, he went for his other passion: music. His work as an international DJ has allowed him to collaborate with worldwide known artists like Lenny Kravitz and Shakira, among others, and to play in Kapital and Fabrik (Madrid), Tito’s (Palma) or Privilege (Ibiza).

During the 2019 season, Fonsi was an official sponsor of Alma Pramac Racing.

In 2017 Fonsi got married to Marta Castro with whom he had two children.