Jeju United (K League 1): every transfer in and out, fees paid and earned, squad market value, €1.7m spent and €1m earned.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-08-03 | Geon-ung Kim | Jeju United | Consadole Sapporo | Free |
| 2026-07-25 | Tae-hee Nam | Jeju United | Brisbane Roar | Free |
| 2026-07-21 | Eraldo Cinari | Al Jabalain | Jeju United | Free |
| 2026-07-17 | Chang-hoon Kwon | Jeju United | Persija | Free |
| 2026-07-16 | Ja-ung Heo | Cheonan City | Jeju United | Free |
| 2026-07-12 | Matheus Aiás | Noah | Jeju United | Free |
| 2026-07-09 | Gytis Paulauskas | Jeju United | Jeonbuk Hyundai Motors | Loan |
| 2026-03-17 | Tobias Figueiredo | Fortaleza Esporte Clube | Jeju United | Free |
| 2026-01-23 | Julien Célestine | Morski Związkowy Klub Sportowy Arka Gdynia Spółka Akcyjna | Jeju United | Free |
| 2026-01-19 | Yuri Tanque | Jeju United | Criciúma EC B | Free |
| 2026-01-19 | Jun-ho Hong | Jeju United | Suwon FC | Free |
| 2026-01-16 | Emerson Negueba | Cuiabá-MT | Jeju United | Free |
| 2026-01-16 | Gytis Paulauskas | Michalovce | Jeju United | €300k |
| 2026-01-16 | Chang-hoon Kwon | Jeonbuk Hyundai Motors | Jeju United | Free |
| 2026-01-16 | Chang-jun Park | Bucheon 1995 | Jeju United | Free |
| 2026-01-16 | Shin-jin Kim | Gangwon Football Club | Jeju United | Free |
| 2026-01-16 | Jung-min Kim | Jeju United | Hwaseong | Free |
| 2026-01-16 | Tae-hyun An | Jeju United | Bucheon 1995 | Free |
| 2026-01-16 | Seong-been Cho | Jeju United | Cheongju | Free |
| 2026-01-16 | Jae-min Jegal | Jeju United | Hwaseong | Free |