A member of the Mercedes Junior Team since 2019,[a] Antonelli made his free practice debut in Formula One at the 2024 Italian Grand Prix.

[11] Antonelli attended ITCS Gaetano Salvemini in Casalecchio di Reno, studying international relations and marketing, and learnt to speak English during his race weekends.

[23] Antonelli entered several major competitions in 2016, achieving top-three finishes in the Italian Cup and Trofeo delle Industrie,[24][25] as well as the WSK Super Master Series in 2017.

Antonelli retired from the final of the World Championship at Portimão with an injury;[43] he collided with the stationary kart of Maya Weug in wet-weather conditions, suffering a broken left tibia and metatarsus.

[48] Three weeks after he turned 15, Antonelli made his junior formulae debut in the fifth round of the 2021 Italian F4 Championship, driving for Prema at the Red Bull Ring.

[69][70] In 2022, Antonelli remained with Prema in Italian F4,[71] also co-signed by the Automobile Club d'Italia as a member of ACI Team Italia by virtue of winning the Supercorso Federale in November 2021.

[74] His fortunes changed with two wins in the next round at Misano,[75] followed by six consecutive victories at Spa-Francorchamps and Vallelunga which propelled him to lead the standings ahead of Rafael Câmara.

[89][90] Following his titles in Italian and ADAC F4, Antonelli represented Team Italy in the Formula 4 Cup discipline of the biennial FIA Motorsport Games at Paul Ricard.

[97] Prior to his main 2023 campaign, Antonelli contested the inaugural F3-level Formula Regional Middle East Championship with Mumbai Falcons.

[107] Antonelli progressed to the Formula Regional European Championship in 2023, remaining with Prema alongside Lorenzo Fluxá, as well as F4 and karting rival Rafael Câmara.

[110] Prior to the season, Marcus Simmons of Autosport compared the intrigue surrounding his campaign to the Formula Three debuts of Ayrton Senna, Mika Häkkinen and Max Verstappen,[111] whilst Salvo Sardina of La Gazzetta dello Sport described him as a "predestinato" (lit. 'predestined').

[115][116] Additional wins from pole position at Mugello and Paul Ricard followed for Antonelli, who became the championship leader going into the summer break, ahead of Martinius Stenshorne.

[138] After qualifying second in Melbourne,[139] he spun into the gravel whilst making up places in the reverse-grid sprint,[b] before battling with Dennis Hauger for the lead of the feature, where he ultimately finished fourth.

[146] After placing outside of the points in Barcelona and Spielberg,[135] Antonelli sat ninth in the standings halfway through the season; Toto Wolff commented that Mercedes were unfazed by his results and that "a champion needs to be thrown in the cold water".

[164][165] Antonelli missed out on his maiden pole position by seventeen-thousandths of a second in Baku,[166] finishing seventh in the sprint and third in the feature, after contact with Zane Maloney in the latter.

[167][168][169] He retired from both races in Lusail, subsequent to a collision with Maini in the sprint and Richard Verschoor in the feature,[170][171] the latter released unsafely into his path in the pit lane.

[172] Antonelli withdrew from the season-ending round at Yas Marina with illness, finishing the season sixth in the standings with two victories, three podiums, four fastest laps and 113 points.

[11][177][178] Following a new rule that re-allowed drivers to hold an FIA Super Licence at the minimum age of 17,[179][180] Antonelli was rumoured to replace Logan Sargeant at Williams midway through the 2024 season;[181] Mercedes denied the move, instead recommending Mick Schumacher for the position.

[182][183] Antonelli made his free practice debut at the 2024 Italian Grand Prix, taking part in the first session in George Russell's W15.

[187][11] Toto Wolff defended Antonelli after the crash,[188] whilst Mark Hughes of Motor Sport compared his free practice debut to that of Tazio Nuvolari.

[196] In May 2023, Antonelli debuted in sportscar racing, competing for his father's AKM Motorsport outfit in the opening round of the Italian GT3 Championship, driving the Mercedes-AMG GT3 Evo.

[203] Antonelli appeared in a cameo role as Matteo in the sports drama film Italian Race[c] (2016),[204] which won four awards at the Nastro d'Argento.