[1] Belgium qualified one player based on the Badminton Junior World Rankings.

[2] Belgium qualified a boys' team based on its performance at the 2017 FIBA 3x3 U18 World Cup.

[4] Belgium qualified a rider based on its performance at the FEI European Junior Jumping Championships.

[7] Belgium qualified one athlete based on its performance at one of the Karate Qualification Tournaments.

[8] Belgium qualified one boat based on its performance at the 2017 World Junior Rowing Championships.