Football Club Seoul (K League 1): every transfer in and out, fees paid and earned, squad market value, €3.5m spent and €4.5m earned. Tracked squad: ACTUAL Value €4.8m vs €9.2m market value. Valued as of 2026-08-25.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-07-01 | Aleksandar Palocevic | Football Club Seoul | Imabari | Free |
| 2026-02-23 | Cheol-won Choi | Football Club Seoul | Gyeongju HNP | Free |
| 2026-01-30 | Jun-yeong Choi | Football Club Seoul | Gimhae City | Free |
| 2026-01-27 | Lucas Silva | FC Seoul | EC Vitória | Loan |
| 2026-01-23 | Juan Antonio Ros | TJ Jinmen Tiger | FC Seoul | Free |
| 2026-01-21 | Min-kyu Song | Jeonbuk Hyundai | FC Seoul | Free |
| 2026-01-16 | Hrvoje Babec | NK Osijek | FC Seoul | — |
| 2026-01-16 | Jeong-beom Son | FC Seoul U18 | FC Seoul | — |
| 2026-01-16 | Leonardo Ruiz | Seongnam FC | FC Seoul | Free |
| 2026-01-16 | Pil-gwan Ko | FC Seoul U18 | FC Seoul | — |
| 2026-01-16 | Sung-yun Gu | Seoul E-Land | FC Seoul | — |
| 2026-01-16 | Leonardo Ruiz | Seongnam | Football Club Seoul | Free |
| 2026-01-16 | Han-min Jung | FC Seoul | Pohang Steelers | Free |
| 2026-01-16 | Seung-beom Son | FC Seoul | Pohang Steelers | — |
| 2026-01-16 | Jae-moon Ryu | Football Club Seoul | Daegu FC | Free |
| 2026-01-16 | Hyun-seo Bae | Football Club Seoul | Gyeongnam | Loan |
| 2026-01-16 | Hyeon-deok Kim | Football Club Seoul | Gimhae City | Loan |
| 2025-11-17 | Ju-hyeok Kang | FC Seoul | Gimcheon Sangmu | Loan |
| 2025-07-31 | Ju-sung Kim | FC Seoul | Sanf. Hiroshima | €1.1m |
| 2025-07-24 | Seong-hoon Cheon | Daejeon Hana C. | FC Seoul | — |