Beşiktaş Jimnastik Kulübü (Super Lig): every transfer in and out, fees paid and earned, squad market value, €249m spent and €128m earned.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-07-01 | Orkun Kökçü | Benfica | Besiktas | €30m |
| 2026-07-01 | Necip Uysal | Besiktas | Retired | — |
| 2026-07-01 | Ernest Muci | Besiktas | Trabzonspor | €8.5m |
| 2026-02-06 | Emmanuel Agbadou | Wolves | Besiktas | €18m |
| 2026-02-06 | Devis Vásquez | Roma | Besiktas | Loan |
| 2026-02-06 | Amir Murillo | Marseille | Besiktas | €5m |
| 2026-02-04 | Hyeon-gyu Oh | Genk | Besiktas | €14m |
| 2026-02-03 | Junior Olaitan | Göztepe | Besiktas | €5m |
| 2026-02-01 | Emrecan Terzi | Besiktas | Sakaryaspor | Loan |
| 2026-01-30 | Kristjan Asllani | Inter | Besiktas | Loan |
| 2026-01-30 | Jonas Svensson | Besiktas | Rosenborg BK | Free |
| 2026-01-28 | Yasin Özcan | Aston Villa | Besiktas | Loan |
| 2026-01-27 | Tammy Abraham | Besiktas | Aston Villa | €21m |
| 2026-01-26 | Tammy Abraham | Roma | Besiktas | €15m |
| 2026-01-22 | Rafa Silva | Besiktas | Benfica | €5m |
| 2026-01-21 | Demir Ege Tıknaz | Besiktas | Braga | €7m |
| 2026-01-14 | Élan Ricardo | Besiktas | Deportes Tolima | Loan |
| 2026-01-12 | Gabriel Paulista | Besiktas | Corinthians | Free |
| 2026-01-06 | Mert Günok | Besiktas | Fenerbahçe | Free |
| 2026-01-05 | Arda Kılıç | Besiktas | Karsiyaka | Loan |