The FIA Formula 2 Championship replaced the GP2 Series from 2017, retaining the same format and machinery but under a rebranded identity. Leclerc arrived having won the GP3 Series as a rookie the previous year with ART Grand Prix, and joined Prema alongside fellow Ferrari Driver Academy member Antonio Fuoco. At 19 years old, he was one of the youngest drivers on the grid and carrying the full weight of Ferrari's junior programme expectations.
Leclerc qualified on pole for the opening feature race at Sakhir and finished third. In the reverse-grid sprint he built a nine-second lead before making an uncommon mid-race pit stop, then overtook 13 drivers in the final nine laps to claim his maiden F2 victory. At Barcelona he won his first feature race, holding off Luca Ghiotto despite a radio failure.
He retired from both races in Monte Carlo — suspension failure in the feature, collision damage in the sprint — while leading the championship. At Baku he dedicated pole position to his father Hervé, who had died four days before the previous round in Baku after a long illness, the elder Leclerc unaware that his son had not yet formally signed his Formula One contract. Leclerc converted the Baku pole to a feature race victory.
A record-equalling sixth consecutive pole at Silverstone preceded a win there. At Spa-Francorchamps, after he was disqualified from a 25-second victory margin in the feature due to excessive skid block wear, he recovered from nineteenth on the grid in the sprint. At Monza, battling Nyck de Vries for the lead on the final lap following a safety car, the pair collided and both finished outside the points. Nevertheless, Leclerc entered the penultimate round at Jerez with a 59-point lead over Oliver Rowland. He required pole position and victory to seal the title in the feature race; he achieved both, his eighth pole of the season holding off Rowland in the closing laps to become the youngest champion in GP2/F2 history at 19 years and 356 days.
At the season finale at Yas Island, he equalled the record with his seventh win of the campaign. He finished 72 points ahead of runner-up Artem Markelov and was named FIA Rookie of the Year.
Leclerc's 2017 campaign is notable for its combination of raw statistical dominance and personal adversity. He became the third rookie F2/GP2 champion after Lewis Hamilton in 2006 and Nico Hülkenberg in 2009, and the fourth overall following Nico Rosberg in 2005. His eight poles set a single-season record for the series. Ferrari moved quickly, signing him to race with Sauber in 2018 — a one-season formation step — before joining the works team in 2019.
The title confirmed the back-to-back GP3/F2 trajectory that would later be replicated by George Russell (2017 GP3, 2018 F2) and Oscar Piastri (2020 F3, 2021 F2), establishing a clear modern benchmark for top Formula One prospects.