Born on 10 April 2004 in Paris, Ismaël Gharbi developed his skills in the capital. He started his journey at Paris FC from the age of 6 to 12 before joining the Paris Saint-Germain Youth Academy in 2016. On 1 August 2021, Gharbi made his professional debut for the club from the capital, coming on as a substitute during a defeat in the Trophée des Champions against LOSC Lille.
Eligible for selection by the French, Tunisian, and Spanish national teams, Paris Saint-Germain's number 35 initially represented the youth teams of France and Spain before expressing his desire in May 2023 to represent Tunisia. On 17 June 2022, Ismaël Gharbi signed his first professional contract with the club. By making six appearances from the bench during the 2022/2023 season with Paris, he officially became a French champion for the first time with Les Rouge et Bleu. He was loaned to FC Stade Lausanne Ouchy for the 2023-2024 season.