Seongnam Yth.: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2020-01-01 | Hyeong-jun Oh | Seongnam Yth. | FC Dongtan U15 | — |
| 2019-01-01 | Seung-bin Jung | Seongnam Yth. | Seongnam FC U15 | — |
| 2014-01-01 | Jae-min Jung | Seongnam Yth. | Bucheon U15 | — |