Jeju SK U18: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-01-16 | Jae-won Heo | Jeju SK U18 | Jeju SK | — |
| 2025-01-17 | Seung-min Joo | Jeju SK U18 | Jeju SK | — |
| 2024-01-01 | Min-jae Park | Jeju United U18 | Yonsei Univ. | — |
| 2024-01-01 | Jun-ha Kim | Jeju United U18 | Soongsil Univ. | — |
| 2024-01-01 | Jae-won Heo | Jeju United U15 | Jeju United U18 | — |
| 2024-01-01 | Byung-wook Choi | Jeju United U18 | Soongsil Univ. | — |
| 2022-01-01 | Seung-min Joo | Iridong MS | Jeju United U18 | — |
| 2022-01-01 | Joon-seob Im | Jeju United U18 | Jeju United | — |
| 2022-01-01 | Jae-min Kim | Jeju United U18 | Sungkyunkwan U. | — |
| 2021-01-01 | Min-jae Park | Dobong MS | Jeju United U18 | Free |
| 2021-01-01 | Jun-ha Kim | Dobong MS | Jeju United U18 | — |
| 2021-01-01 | Byung-wook Choi | Dongbuk MS | Jeju United U18 | — |
| 2020-01-01 | Dong-hyun Kim | Jeju United U18 | Seogwipo HS | — |
| 2019-01-04 | Jin-su Seo | Jeju United U18 | Jeju United | — |
| 2019-01-04 | Dong-ryul Lee | Jeju United U18 | Jeju United | — |
| 2019-01-01 | Joon-seob Im | YI U15 Wonsam | Jeju United U18 | — |
| 2019-01-01 | Jae-min Kim | Dongbuk MS | Jeju United U18 | — |
| 2018-01-01 | Dong-hyun Kim | Jeju United U15 | Jeju United U18 | — |
| 2017-01-01 | Eui-hyeong Lee | Jeju United U18 | Dankook Univ | — |
| 2016-01-01 | Tae-wook Jeong | Jeju United U18 | Ajou University | — |