[1] Born in Buenos Aires, in a family with Italian origins,[2] Marco Pellegrino first played youth tennis at high level, before switching to football.
[6] Marco Pellegrino made his professional debut for Platense on the 14 March 2023, starting the Primera División game against Vélez Sarsfield.
[9] On 29 October 2023, Pellegrino made his debut for Milan in a 2–2 away draw with Napoli, coming on as a substitute for the injured Pierre Kalulu 19 minutes into the game.
On 18 January 2025, Pellegrino joined Primera División club Huracán, on a six-month loan until the end of the season.
Pellegrino was part of the 34 players that were called up to the Argentina national team for the 2026 FIFA World Cup qualification matches against Paraguay and Peru on 12 and 17 October 2023, respectively.