[12] Despite struggling to push down fully on the car's pedals owing to his low height at the start of the season, Hadjar was able to achieve his first single-seater win at Spa during the third round.

[14] The final three rounds of the season, were hampered by three retirements, but he still managed to score a decent haul of points to finish seventh in the standings, claiming second in the junior class to Victor Bernier.

[18] However in the penultimate round in Paul Ricard, Hadjar scored a pole position and held off Ayumu Iwasa to win his first race of the year.

[23] Hadjar made his debut at the Formula Regional level in 2021, competing in the first three rounds of the F3 Asian Championship with Evans GP.

Hadjar's main campaign would lie in the Formula Regional European Championship, where he partnered Zane Maloney, Léna Bühler and fellow countryman Hadrien David at R-ace GP.

[31] He then proceeded to score his first podium at the next event in Barcelona,[32] and achieved his first Formula Regional victory in the first race on the streets of Monaco, from pole position.

[41] Hadjar secured his first win of the year during the first race at the Dubai Autodrome, where he withstood heavy pressure from Paul Aron.

[46] He started his season out in the best way possible, inheriting victory in the Sakhir sprint race after original winner Oliver Bearman had received a five-second time penalty for track limits infringements.

[50] Hadjar returned to the podium during the feature race, benefitting from a last corner collision between Bearman and Grégoire Saucy to finish third.

[60][61] After scoring one point on Saturday,[62] Hadjar converted his pole into a lights-to-flag feature race win in rainy conditions.

[67] A mixed-weather qualifying session at Spa yielded a disappointing 23rd place for Hadjar,[68][69] though he progressed enough to score two points in the sprint race, where he finished ninth.

[72][73] In a close championship fight between seven drivers, Hadjar put a dent into his title aspirations by crashing at the final corner during qualifying in Monza, meaning he would start from 16th.

[85][86] This was followed up by a charge from 18th to eighth in the Baku sprint race, though he was demoted to 11th for illegally overtaking Jack Doohan during the safety car restart.

[89] Hadjar qualified tenth in Monaco meaning he would start the sprint from pole;[90] he led until lap 6 when a mechanical failure put him out of the race.

[100] Hadjar qualified fifth in Hungary, and he held off championship leader Frederik Vesti to finish eighth in the sprint race.

[102] A week later, Hadjar crashed into the pit exit wall during the feature race in Spa-Francorchamps, ending his chance for points.

[107] At the season finale in Yas Marina Hadjar ran second in the opening laps of the sprint race, though he eventually dropped to fifth by the end.

[111] Hadjar switched to Campos Racing for the 2024 Formula 2 season, teaming up with fellow Red Bull junior Pepe Martí.

[120] Following his involvement in a multi-car collision during the Imola sprint race, Hadjar bounced back by winning his second successive feature event, having defended against Bortoleto.

[125] He retired from the sprint after spinning out at Copse corner, but bounced back to win the feature race, inheriting victory after Jak Crawford had been penalised for an unsafe release; this put Hadjar into the lead of the championship.

[128] However, the following round at Monza yielded no points for Hadjar, whereas Bortoleto profited from a well-timed safety car to win the feature race.

[134] In the feature race Hadjar benefitted from a safety car that allowed him to jump up to third place behind title rivals Bortoleto and Paul Aron.

[135] Hadjar qualified fourth in Abu Dhabi and finished fifth on Saturday, after suffering front wing damage on the first lap after contact with Kush Maini.

Hadjar would end his final F2 season as runner-up in the Drivers' Championship finishing with four wins, eight podiums, one pole position, one fastest lap and 192 points compared to teammate Marti's 62.

[142] Hadjar made his free practice debut at the 2023 Mexico City Grand Prix with Scuderia AlphaTauri, to fulfill the mandatory rookie driver rule.

[148][149] Later that year, Hadjar took part in free practice during the Abu Dhabi Grand Prix, driving Max Verstappen's RB20.

[150][151] Hadjar also drove the RB20 in the post-season Abu Dhabi rookie test, where his pace — faster than that of future teammate Yuki Tsunoda — impressed team principal Christian Horner.