Isack Alexandre Hadjar is a French and Algerian racing driver, who is contracted to compete in Formula One for Racing Bulls.
Born and raised in Paris to an Algerian family, Hadjar began competitive kart racing aged seven. After debuting in sportscar racing at the Ginetta Junior Winter Series, Hadjar graduated to junior formulae in 2019. He finished third in the 2020 French F4 Championship with FFSA Academy, before progressing to the Formula Regional European Championship in 2021, achieving multiple victories as he finished fifth in his rookie season. He then entered Formula Regional Asian and FIA Formula 3 in 2022 with Hitech, placing third in the former and achieving multiple wins in both. Hadjar graduated to FIA Formula 2 in 2023, finishing runner-up to Gabriel Bortoleto the following season with Campos; his successes in Formula 2 saw him nicknamed "Le Petit Prost" in French media.
A member of the Red Bull Junior Team since 2022, Hadjar signed for Racing Bulls in 2025, replacing Liam Lawson to partner Yuki Tsunoda. Hadjar is contracted to remain at Racing Bulls until at least the end of the 2025 season.