Pierre Kalulu is a French professional footballer who plays as a central defender for AC Milan in the Italian Serie A. Born on October 21, 1995, in Paris, France, he began his career with Ligue 1 side AS Monaco before joining AC Milan in 2017.

Kalulu made his debut for the club in a 4-2 win over Bologna on September 18, 2017. He quickly established himself as a regular starter and has since become one of the most important players for AC Milan. In his first season with the club, he played 36 games and scored two goals, helping AC Milan to secure a spot in the UEFA Champions League group stage.

In the following seasons, Kalulu continued to perform well for AC Milan, playing in all but three of the team's league matches during the 2018-19 season. He also featured prominently in the team's successful campaign in the Europa League, where they reached the semi-finals.

Kalulu's performances have not gone unnoticed, and he was named the Serie A Player of the Month for November 2019. He also received recognition from the Serie A Players' Committee, which voted him the Best Young Player of the Season in 2019.

Despite his success at AC Milan, Kalulu has not always been without controversy. In February 2020, he was sent off in a match against Udinese, and later faced criticism for his behavior towards the referee after the game. However, he responded by apologizing for his actions and promising to learn from them.

Overall, Pierre Kalulu has been a key player for AC Milan and has helped the club achieve great success both domestically and internationally. With his versatility and strong defensive abilities, he is expected to continue making significant contributions to the team in the future.