Union SG Yth.: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2022-07-01 | Daniel Tshilanda Kabongo | Union SG Yth. | Union SG U18 | — |
| 2021-07-01 | Nathan Huygevelde | Union SG Yth. | Union SG U18 | — |
| 2020-07-01 | Nolhan Courtens | Union SG Yth. | KV Mechelen Yth | Free |
| 2020-07-01 | Nathan Huygevelde | KAA Gent Youth | Union SG Yth. | Free |
| 2019-07-01 | Nolhan Courtens | Tubize Yth. | Union SG Yth. | Free |
| 2018-07-01 | Ismaël El Abbassi | Union SG Yth. | Standard Liège | Free |
| 2018-07-01 | Brahim Ghalidi | Union SG Yth. | STVV Youth | Free |
| 2017-07-01 | Amadou Diallo | Union SG Yth. | Zulte W. Youth | Free |
| 2015-07-01 | Brahim Ghalidi | Anderlecht Yth. | Union SG Yth. | Free |
| 2013-07-01 | Ibrahim Salah | Union SG Yth. | Beersch. Youth | Free |