Fernández competed in the 2015 Red Bull MotoGP Rookies Cup, finishing 3rd in Brno, 2nd in Misano, and 2nd in Aragón in his rookie campaign, ending the season 7th in the overall standings, with 121 points. He competed again in 2016, this time finishing on the podium six times (twice 1st, three times 2nd, and once 3rd), winning two races in Assen (both from Pole Position), and finishing the season in 3rd overall.[2] He was the 2018 FIM CEV Moto3 Junior World Champion.
Fernández would make three wild-card round entries for the MahindraAspar Team in 2017, finishing 25th in Jerez, retiring in Assen, and finishing 22nd in Germany.
He would once again make four wild-card round entries for the Aspar Team in 2018, this time riding KTM bikes used by the Aspar team. He improved his prior season's results, and earned himself a full time ride for next year with his 10th place in Barcelona, 9th place in Germany, 17th place in Aragón, and 13th place in Valencia.
In his first full year in Moto3, Fernández had a decent rookie season, finishing in the points ten times, finishing in the top-ten six times, with his season's highest being a 5th-place finish in Germany. He ended the 2019 season 21st in the championship standings, with 60 points.
Red Bull KTM Ajo (2020)
Due to his good performances, Fernández was given a contract by the Red Bull KTMAjo team for the 2020 season, which saw him steadily improve over the course of the year. He had six Pole Positions during the season (Czechia, Austria, Misano, Aragón, Valencia, and Portimao), two 3rd places in Aragón and Valencia, and won the European Grand Prix, and Portuguese Grand Prix.[4][5] He ended the season 4th in the championship standings, with 159 points, just 15 points away from 1st.
Moto2 World Championship
Red Bull KTM Ajo (2021)
Being promoted to Moto2, but staying with the Red Bull KTM Ajo family, Fernández had the best rookie season ever in Moto2, beating several records of Marc Márquez.[6] He won eight races (Portugal, France, Netherlands, Austria, Aragón, Rimini, USA, and Valencia),[7] had seven Pole Positions, stood on the podium 12 times, finished outside of the top-seven just the three times he retired from a race (Germany, Great Britain, Misano), and finished second in the standings, just 4 points away from teammate Remy Gardner, who won the title.
MotoGP World Championship
Tech3 KTM Factory Racing (2022)
In August 2021, it was announced that both Fernández and Gardner would be promoted to MotoGP, riding for Red Bull KTMTech3 in the 2022 season.[8] Fernández becomes just the third rider to be promoted to MotoGP after one lone season in Moto2, following Maverick Viñales, and Joan Mir.