1.FSV Mainz 05 (Bundesliga): every transfer in and out, fees paid and earned, and the market value of the squad. €176m spent, €296m earned. Tracked squad: ACTUAL Value €102m vs €147m market value. Valued as of 2026-09-02.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-09-02 | Hyun-seok Hong | 1.FSV Mainz 05 | FC Midtjylland | Loan |
| 2026-09-01 | Andreas Hanche-Olsen | 1.FSV Mainz 05 | Chicago Fire Soccer Club | Free |
| 2026-08-28 | William Bøving | 1.FSV Mainz 05 | 1. FC Nürnberg | Loan |
| 2026-07-30 | Alexander Schwolow | Hearts | 1.FSV Mainz 05 | Free |
| 2026-07-17 | Nelson Weiper | 1.FSV Mainz 05 | Sportklub Puntigamer Sturm Graz | Loan |
| 2026-07-16 | Ben Bobzien | 1.FSV Mainz 05 | Dynamo Dresden | €1m |
| 2026-07-16 | Niklas Tauer | 1.FSV Mainz 05 | TSV Havelse | Free |
| 2026-07-06 | Lasse Rieß | 1.FSV Mainz 05 | Fortuna Düsseldorf | Loan |
| 2026-07-01 | Eric Martel | 1.FC Köln | Mainz | Free |
| 2026-07-01 | Ransford Königsdörffer | Hamburg | Mainz | Free |
| 2026-07-01 | Sheraldo Becker | CA Osasuna | Mainz | €500k |
| 2026-07-01 | Sota Kawasaki | Kyoto Sanga | Mainz | €1m |
| 2026-07-01 | Nick Cherny | Borussia Dortmund | 1.FSV Mainz 05 | Free |
| 2026-07-01 | Fabio Gruber | 1. FC Nürnberg | 1.FSV Mainz 05 | €3.5m |
| 2026-07-01 | Daniel Batz | Mainz | Mönchengladbach | Free |
| 2026-07-01 | Kasey Bos | Mainz | Excelsior | Loan |
| 2026-07-01 | Nikolas Veratschnig | Mainz | Salzburg | €3.5m |
| 2026-07-01 | Tom Krauß | Mainz | 1.FC Köln | €3.5m |
| 2026-07-01 | T. Müller | 1.FSV Mainz 05 | TSG 1899 Hoffenheim | Free |
| 2026-07-01 | J. Amann | 1.FSV Mainz 05 | Viktoria Köln | Free |