Xavier Tshimanga Kamaluba Ntite Mukendi Mpoyi Mbuyamba (born 31 December 2001) is a Dutch professional footballer who plays as a centre-back for Austrian Bundesliga club LASK. Mbuyamba made his professional debut for MVV Maastricht in 2018 and became the club's youngest-ever debutant, before moving to FC Barcelona the following year. After a season in Spain, he joined Premier League side Chelsea where he has continued his progression with the club's development side. He left Chelsea on a permanent deal on September 1, 2022 to join Eredivisie side, FC Volendam. He is also a Dutch youth international and has represented the Netherlands U19 team since 2019, although he remains eligible to represent DR Congo through descent.