JEF United (J1 League): every transfer in and out, fees paid and earned, squad market value, €1.8m spent and €1.3m earned.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-07-31 | Takahiro Iida | Football Club Mito HollyHock | JEF United | Free |
| 2026-07-28 | Matheus Índio | Atlético GO | JEF United | Free |
| 2026-07-28 | Issei Takahashi | JEF United | Rakuten Vissel Kobe | Free |
| 2026-07-20 | Ken Yamura | Fujieda MYFC | JEF United | Free |
| 2026-07-06 | Carlinhos Junior | JEF United | Omiya Ardija | Free |
| 2026-07-04 | Leonardo Rocha | Raków Częstochowa | JEF United | €1.1m |
| 2026-07-01 | Erison | Kawasaki Frontale | JEF United | Free |
| 2026-07-01 | Daniel Hall | Auckland FC | JEF United | Free |
| 2026-07-01 | Takuro Iwai | JEF United | Blaublitz Akita | Loan |
| 2026-07-01 | Yuma Igari | JEF United | Vanraure Hachinohe | Loan |
| 2026-07-01 | Tomoya Wakahara | JEF United | Hitachi Kashiwa Reysol | Free |
| 2026-02-01 | Makoto Himeno | JEF United U18 | JEF Utd. Chiba | — |
| 2026-02-01 | Takumi Matsumura | Takushoku Univ. | JEF Utd. Chiba | Free |
| 2026-02-01 | Sota Matsubara | JEF United | Sagan Tosu | Free |
| 2026-02-01 | Gentaro Yoshida | JEF United | Osaka | Loan |
| 2026-02-01 | Masamichi Hayashi | JEF United | Imabari | Loan |
| 2026-02-01 | Soshiro Tanida | JEF United | Rayluck Shiga | Loan |
| 2026-01-12 | Rikuto Ishio | Vegalta Sendai | JEF Utd. Chiba | — |
| 2026-01-12 | Taiki Amagasa | Oita Trinita | JEF Utd. Chiba | — |
| 2026-01-12 | Takumi Tsukui | RB Omiya | JEF Utd. Chiba | — |