Hadjar had graduated to Formula 2 in 2023 after a competitive FIA Formula 3 campaign with Hitech Grand Prix, where he finished fourth in the championship. A member of the Red Bull Junior Team since 2022, he moved to Campos Racing for 2024 alongside fellow Red Bull junior Pepe Martí. His opening Formula 2 season had yielded 55 points, but the 2024 campaign showed a markedly elevated level of performance from the outset.
Hadjar claimed his first Formula 2 feature race victory at Melbourne, having been demoted from the sprint result by penalty after a first-corner incident. A second consecutive feature win followed at Imola, where he hunted down Oliver Bearman and inherited the lead after a slow stop for the early race leader. French media coined the "le Petit Prost" moniker after Melbourne, drawing a comparison to Alain Prost's calculated racecraft.
Additional victories came at Silverstone — where he inherited the win after Jak Crawford's penalty — and Spa-Francorchamps, where he took the lead during the pit stop phase and defended against Bortoleto in the closing laps to score his fourth win of the season. By the summer break Hadjar led the championship by 36 points over Bortoleto.
The summer break proved a turning point. A scoreless Monza round, despite qualifying on the front row, was compounded by Bortoleto's last-to-first victory. Two further non-scoring Baku rounds followed — Hadjar had crashed in qualifying with overheating brakes and was forced to start from twentieth in both races. Bortoleto overtook him in the standings.
Hadjar mounted a recovery at Qatar, where penalty against Bortoleto after the feature race reduced the deficit to half a point entering Abu Dhabi — the tightest imaginable margin over a season of 28 races.
Qualifying fourth at Yas Island, Hadjar finished fifth in the sprint, with Bortoleto second. Entering the feature race, Hadjar trailed by four points. The race ended Hadjar's title hopes immediately: he stalled on the grid at the start, unable to participate meaningfully. Bortoleto finished second, clinching the championship. Hadjar's own words on the grid — "all that hard work for this to happen, I can't believe it, this is the worst moment of my life" — reflected the devastation of a title lost to a mechanical moment rather than a racing error.
Hadjar finished the season with four victories, eight podiums, one pole position, one fastest lap, and 192 points in the Drivers' Championship.
Despite the championship defeat, Hadjar's 2024 season was sufficient to confirm his readiness for Formula One. He joined Racing Bulls for 2025 alongside Yuki Tsunoda — later Liam Lawson — and by December 2025 was announced as Max Verstappen's teammate at Red Bull for 2026, a promotion that traced directly to his performances throughout the 2024 Formula 2 title fight.