Mariners Roster & Staff
Transactions
| Date | Transaction |
| 06/30/19 | Seattle Mariners signed SS Mike Salvatore. |
| 06/29/19 | Seattle Mariners sent RHP Sam Tuivailala on a rehab assignment to Arkansas Travelers. |
| 06/28/19 | Texas Rangers claimed LHP Jesse Biddle off waivers from Seattle Mariners. |
| 06/25/19 | Baltimore Orioles claimed RHP Tayler Scott off waivers from Seattle Mariners. |
| 06/23/19 | Seattle Mariners optioned RHP Gerson Bautista to Tacoma Rainiers. |
| 06/23/19 | Seattle Mariners designated LHP Jesse Biddle for assignment. |
| 06/23/19 | Seattle Mariners transferred RHP Chasen Bradford from the 10-day injured list to the 60-day injured list. Right forearm strain. |
| 06/23/19 | Seattle Mariners selected the contract of Matt Carasiti from Tacoma Rainiers. |
| 06/23/19 | Seattle Mariners selected the contract of RHP Mike Wright from Tacoma Rainiers. |
| 06/22/19 | Seattle Mariners sent RHP Sam Tuivailala on a rehab assignment to Everett AquaSox. |
| 06/21/19 | C Jordan Pacheco assigned to Seattle Mariners. |
| 06/21/19 | Seattle Mariners optioned RHP Tayler Scott to Tacoma Rainiers. |
| 06/21/19 | Seattle Mariners recalled RHP Dan Altavilla from Tacoma Rainiers. |
| 06/17/19 | Seattle Mariners signed free agent RHP Matt Mogollon to a minor league contract. |
| 06/17/19 | Seattle Mariners signed free agent RHP Robert Winslow to a minor league contract. |
| 06/17/19 | Seattle Mariners signed SS Caleb Ricca. |
| 06/17/19 | Seattle Mariners signed free agent RHP Bernie Martinez to a minor league contract. |
| 06/17/19 | Seattle Mariners signed RHP Fred Villarreal. |
| 06/16/19 | Seattle Mariners selected the contract of C Austin Nola from Tacoma Rainiers. |
| 06/15/19 | Seattle Mariners traded 1B Edwin Encarnacion and cash to New York Yankees for Juan Then. |
| 06/15/19 | Seattle Mariners traded 1B Edwin Encarnacion and cash to New York Yankees for Juan Then. |
| 06/14/19 | Seattle Mariners activated SS J.P. Crawford from the 10-day injured list. |
| 06/14/19 | Seattle Mariners sent RHP Felix Hernandez on a rehab assignment to Tacoma Rainiers. |
| 06/14/19 | Seattle Mariners placed RHP Brandon Brennan on the 10-day injured list. Right shoulder strain. |
| 06/14/19 | Seattle Mariners recalled Matt Festa from Tacoma Rainiers. |
| 06/14/19 | Seattle Mariners optioned 2B Shed Long to Tacoma Rainiers. |
| 06/14/19 | Seattle Mariners signed free agent RHP Evan Johnson to a minor league contract. |
| 06/13/19 | Seattle Mariners signed free agent RHP Michael Stryffeler to a minor league contract. |
| 06/12/19 | RHP George Kirby assigned to Seattle Mariners. |
| 06/12/19 | LHP Brandon Williamson assigned to Seattle Mariners. |
| 06/11/19 | Seattle Mariners activated 2B Dee Gordon from the 10-day injured list. |
| 06/11/19 | Seattle Mariners optioned RHP Matt Festa to Tacoma Rainiers. |
| 06/11/19 | Seattle Mariners signed free agent RHP Nick Duron to a minor league contract. |
| 06/11/19 | Seattle Mariners sent SS J.P. Crawford on a rehab assignment to Modesto Nuts. |
| 06/10/19 | Seattle Mariners signed RHP Jarod Bayless. |
| 06/10/19 | Seattle Mariners signed SS Patrick Frick. |
| 06/10/19 | Seattle Mariners signed RHP Logan Rinehart. |
| 06/10/19 | Seattle Mariners signed SS Cody Grosse. |
| 06/10/19 | Seattle Mariners signed RHP Brock Minich. |
| 06/10/19 | Seattle Mariners signed RHP Tyler Driver. |
| 06/10/19 | Seattle Mariners signed LF Cade Marlowe. |
| 06/10/19 | Seattle Mariners signed RHP Kipp Rollings. |
| 06/10/19 | Seattle Mariners signed CF Antoine Mistico. |
| 06/10/19 | Seattle Mariners signed RHP Reid Morgan. |
| 06/10/19 | Seattle Mariners signed RHP Ty Adcock. |
| 06/10/19 | Seattle Mariners signed C Anthony Lepre. |
| 06/10/19 | Seattle Mariners signed RHP Garrett Westberg. |
| 06/10/19 | Seattle Mariners signed RHP Tim Elliott. |
| 06/10/19 | Seattle Mariners signed 3B Austin Shenton. |
| 06/10/19 | Seattle Mariners signed RHP Kyle Hill. |
| 06/10/19 | Seattle Mariners signed C Carter Bins. |
| 06/10/19 | Seattle Mariners signed RHP Travis Kuhn. |
| 06/10/19 | Seattle Mariners signed RHP Reeves Martin. |
| 06/10/19 | Seattle Mariners signed RF Trent Tingelstad. |
| 06/08/19 | RHP Matt Martin assigned to Seattle Mariners. |
| 06/08/19 | LHP Nate Fisher assigned to Seattle Mariners. |
| 06/08/19 | Seattle Mariners signed SS Utah Jones. |
| 06/07/19 | Seattle Mariners sent 2B Dee Gordon on a rehab assignment to Tacoma Rainiers. |
| 06/07/19 | Seattle Mariners selected the contract of LHP Sean Nolin from Long Island Ducks. |
| 06/07/19 | Seattle Mariners placed RF Mitch Haniger on the 10-day injured list. Ruptured testicle. |
| 06/07/19 | Chicago White Sox claimed RHP Jimmy Cordero off waivers from Seattle Mariners. |
| 06/07/19 | Seattle Mariners selected the contract of Tayler Scott from Tacoma Rainiers. |
| 06/07/19 | Seattle Mariners signed free agent RHP Matt Carasiti to a minor league contract. |
| 06/05/19 | Seattle Mariners placed CF Braden Bishop on the 10-day injured list. Lacerated spleen. |
| 06/05/19 | Gerson Bautista roster status changed by Seattle Mariners. |
| 06/05/19 | Seattle Mariners optioned RHP Andrew Moore to Arkansas Travelers. |
| 06/04/19 | Seattle Mariners recalled Andrew Moore from Arkansas Travelers. |
| 06/04/19 | Seattle Mariners placed RHP Connor Sadzeck on the 10-day injured list retroactive to June 3, 2019. Right elbow inflammation. |
| 06/04/19 | Seattle Mariners activated LF Mac Williamson. |
| 06/03/19 | Seattle Mariners signed free agent RHP Ricardo Volquez to a minor league contract. |
| 06/03/19 | Seattle Mariners placed RHP Chasen Bradford on the 10-day injured list. Right forearm strain. |
| 06/03/19 | Seattle Mariners recalled Matt Festa from Tacoma Rainiers. |
| 06/02/19 | Seattle Mariners traded RF Jay Bruce to Philadelphia Phillies for 3B Jake Scheiner and cash. |
| 06/02/19 | Seattle Mariners recalled CF Braden Bishop from Tacoma Rainiers. |
| 06/02/19 | Minnesota Twins traded OF John Andreoli to Seattle Mariners. |
| 06/02/19 | Seattle Mariners traded RF Jay Bruce to Philadelphia Phillies for 3B Jake Scheiner and cash. |
| 06/01/19 | Seattle Mariners signed free agent SS Kelby Tomlinson to a minor league contract. |
| 06/01/19 | Seattle Mariners signed free agent LF Jaycob Brugman to a minor league contract. |