Marlins Roster & Staff
Transactions
| Date | Transaction |
| 01/21/20 | Miami Marlins invited non-roster LHP Alex Vesia to spring training. |
| 01/21/20 | Miami Marlins invited non-roster SS Jose Devers to spring training. |
| 01/21/20 | Miami Marlins invited non-roster SS Eddy Alvarez to spring training. |
| 01/21/20 | Miami Marlins invited non-roster LHP Trevor Rogers to spring training. |
| 01/21/20 | Miami Marlins invited non-roster LHP Dylan Lee to spring training. |
| 01/21/20 | Miami Marlins invited non-roster LHP Braxton Garrett to spring training. |
| 01/21/20 | Miami Marlins invited non-roster RHP Tommy Eveld to spring training. |
| 01/21/20 | Miami Marlins invited non-roster LHP Daniel Castano to spring training. |
| 01/21/20 | Miami Marlins invited non-roster RF JJ Bleday to spring training. |
| 01/21/20 | Miami Marlins invited non-roster LF Victor Victor Mesa to spring training. |
| 01/21/20 | Miami Marlins invited non-roster CF Brian Miller to spring training. |
| 01/21/20 | Miami Marlins invited non-roster RF Jerar Encarnacion to spring training. |
| 01/21/20 | Miami Marlins released LHP Brian Moran. |
| 01/16/20 | Miami Marlins signed free agent C Gabriel Flores to a minor league contract. |
| 01/16/20 | Miami Marlins signed free agent RHP Kendry Montesino to a minor league contract. |
| 01/15/20 | New York Yankees traded LHP Stephen Tarpley to Miami Marlins for cash and 3B James Nelson. |
| 01/15/20 | New York Yankees traded LHP Stephen Tarpley to Miami Marlins for cash and 3B James Nelson. |
| 01/15/20 | Miami Marlins designated LHP Brian Moran for assignment. |
| 01/14/20 | Miami Marlins traded LF Austin Dean to St. Louis Cardinals for RF Diowill Burgos. |
| 01/14/20 | Miami Marlins traded LF Austin Dean to St. Louis Cardinals for RF Diowill Burgos. |
| 01/10/20 | Miami Marlins traded RHP Austin Brice to Boston Red Sox for 2B Angeudis Santos. |
| 01/10/20 | Miami Marlins traded RHP Austin Brice to Boston Red Sox for 2B Angeudis Santos. |
| 01/09/20 | Miami Marlins signed free agent C Francisco Cervelli. |
| 01/09/20 | Miami Marlins designated LF Austin Dean for assignment. |
| 01/07/20 | Miami Marlins signed free agent OF Corey Dickerson. |
| 01/07/20 | Miami Marlins designated RHP Austin Brice for assignment. |
| 01/06/20 | Miami Marlins traded RHP Kyle Keller to Los Angeles Angels for C Jose Estrada. |
| 01/06/20 | Miami Marlins traded RHP Kyle Keller to Los Angeles Angels for C Jose Estrada. |
| 01/06/20 | Miami Marlins signed free agent RHP Ryan Cook to a minor league contract and invited him to spring training. |
| 01/06/20 | Miami Marlins signed free agent SHP Pat Venditte to a minor league contract and invited him to spring training. |
| 01/03/20 | Jon Berti changed number to 5. |
| 01/03/20 | Ryne Stanek changed number to 55. |
| 01/03/20 | Lewis Brinson changed number to 25. |