On 25 June 2021, Mayulu signed a new three-year youth contract with
Paris Saint-Germain (PSG). On 25 October 2023, he scored the winning goal in a 1–0
UEFA Youth League win over the
AC Milan under-19s, a goal that was described by
Le Parisien as "superb". Less than a month later on 14 November, he was called up by senior head coach
Luis Enrique for his first training session with the first team. In December 2023, ''
L'Équipe'' described Mayulu as one of the "most promising" players in the
Paris Saint-Germain Youth Academy. On 7 January 2024, Mayulu made his professional debut for PSG as a substitute in a 9–0
Coupe de France win over
Revel in the round of 64. Five days later, PSG announced that he would integrate the first team as part of the "elite group", joining teammates
Ethan Mbappé and
Warren Zaïre-Emery. In the round of 32 of the Coupe de France on 20 January, Mayulu scored his first professional goal, a lob over the goalkeeper in a 4–1 victory against
Orléans. On 18 March, he made his
Ligue 1 debut as a substitute in a 6–2 win over
Montpellier. On 6 April, he started his first senior match against
Clermont; he went on to score a goal that was later disallowed by
VAR due to a foul by his teammate in the build-up. On 24 April, Mayulu made his second start for PSG in a match against
Lorient, providing his first career assist for
Ousmane Dembélé's opening goal in a 4–1 victory. He signed his first professional contract on 20 May, a deal until 30 June 2027. On 19 October 2024, Mayulu scored the opening goal of a 4–2 win over
Strasbourg, his first in Ligue 1. On 19 February 2025, he scored his first
UEFA Champions League goal in a 7–0 win over
Brest in the knockout round play-offs. On 31 May 2025, Mayulu came off the bench to score the final goal in the
2025 UEFA Champions League final, a 5–0 victory over
Inter Milan, to become at 19 years and 14 days the youngest Frenchman to score in a UEFA club competition final, and the third-youngest player, behind
Patrick Kluivert and
Brian Kidd, ever to score in a Champions League final. The following month, on 15 June, Mayulu scored PSG’s third goal in a 4–0 win against
Atlético Madrid in the
2025 FIFA Club World Cup, to become at 19 years and 28 days the youngest French player to score in the
Club World Cup, surpassing the previous record of 20 years and 297 days set by
Nicolas Anelka in the
2000 edition. == International career ==