Seattle Sounders FC (Major League Soccer): every transfer in and out, fees paid and earned, squad market value, €9.7m spent and €11m earned.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-04-03 | Peter Kingston | Tacoma Defiance | Seattle | — |
| 2026-03-27 | Georgi Minoungou | Seattle | Colorado | €1.8m |
| 2026-02-18 | Reed Baker-Whiting | Seattle | Nashville | €675k |
| 2026-02-02 | Obed Vargas | Seattle | Atlético | €3m |
| 2026-01-13 | Yu Tsukanome | Tacoma Defiance | Seattle | — |
| 2026-01-13 | Sebastian Gomez | Tacoma Defiance | Seattle | — |
| 2026-01-08 | Nikola Petković | Charlotte | Seattle | Loan |
| 2026-01-01 | Danny Leyva | Seattle | Necaxa | €1m |
| 2025-12-17 | Ryan Sailor | Miami | Seattle | Free |
| 2025-12-17 | Max Anchor | Vancouver | Seattle | Free |
| 2025-12-16 | Jon Bell | Seattle | Austin | Free |
| 2025-12-16 | Hassani Dotson | Minnesota | Seattle | Free |
| 2025-09-08 | Cody Baker | Seattle | Sacramento FC | Loan |
| 2025-07-29 | Snyder Brunell | Tacoma Defiance | Seattle | — |
| 2025-05-08 | Osaze De Rosario | Tacoma Defiance | Seattle | — |
| 2025-02-15 | Josh Atencio | Seattle | Colorado | €1.3m |
| 2025-01-31 | Kee-hee Kim | Ulsan HD | Seattle | Free |
| 2025-01-13 | Paul Arriola | Dallas | Seattle | — |
| 2025-01-08 | Jesús Ferreira | Dallas | Seattle | €1.4m |
| 2024-08-28 | Georgi Minoungou | Tacoma Defiance | Seattle | — |