This is a list of Belgian football transfers for the 2021 summer transfer window. Only transfers involving a team from the professional divisions are listed, including the 18 teams in the Belgian First Division A and the 8 teams playing in the Belgian First Division B.
The summer transfer window opened on 1 July 2021 and towards the end of August 2021.
Note that several transfers were announced prior to the opening date. Furthermore, players without a club may join one at any time, either during or in between transfer windows. After the transfer window closes a few completed transfers might still be announced a few days later.
Arjan Swinkels is a Dutch retired professional footballer who played as a centre-back. He is the head of Willem II's youth department.
The 2021–22 season was the 114th season in the existence of R.S.C. Anderlecht and the club's 86th consecutive season in the top flight of Belgian football. In addition to the domestic league, Anderlecht participated in this season's edition of the Belgian Cup and the UEFA Europa Conference League.
The 2021–22 season was the 119th season in the existence of K.A.A. Gent and the club's 33rd consecutive season in the top flight of Belgian football. In addition to the domestic league, Gent participated in this season's editions of the Belgian Cup and the UEFA Europa Conference League.
The 2021–22 season was the 118th season in the existence of K.V. Mechelen and the club's third consecutive season in the top flight of Belgian football. In addition to the domestic league, Mechelen participated in this season's edition of the Belgian Cup.
The 2022–23 season was the 35th in the history of K.R.C. Genk and their 28th consecutive season in the top flight. The club participated in the Belgian Pro League and the Belgian Cup.
The following article is a summary of the 2022–23 football season in Belgium, which is the 120th season of competitive football in the country and will run from July 2022 until June 2023.