Red Sox Roster & Staff
Transactions
| Date | Transaction |
| 07/31/21 | Boston Red Sox activated RHP Hansel Robles. |
| 07/31/21 | Boston Red Sox placed LHP Darwinzon Hernandez on the 10-day injured list. Right oblique strain. |
| 07/31/21 | Boston Red Sox sent LHP Chris Sale on a rehab assignment to Worcester Red Sox. |
| 07/31/21 | Boston Red Sox optioned C Connor Wong to Worcester Red Sox. |
| 07/31/21 | Boston Red Sox activated LHP Austin Davis. |
| 07/30/21 | Pittsburgh Pirates traded LHP Austin Davis to Boston Red Sox for 2B Michael Chavis. |
| 07/30/21 | Boston Red Sox activated RHP Hirokazu Sawamura. |
| 07/30/21 | Boston Red Sox designated CF Marcus Wilson for assignment. |
| 07/30/21 | Minnesota Twins traded RHP Hansel Robles to Boston Red Sox for RHP Alex Scherff. |
| 07/30/21 | Minnesota Twins traded RHP Hansel Robles to Boston Red Sox for RHP Alex Scherff. |
| 07/30/21 | Pittsburgh Pirates traded LHP Austin Davis to Boston Red Sox for 2B Michael Chavis. |
| 07/30/21 | Boston Red Sox sent SS Marwin Gonzalez on a rehab assignment to Worcester Red Sox. |
| 07/30/21 | Boston Red Sox recalled SS Jonathan Arauz from Worcester Red Sox. |
| 07/29/21 | Boston Red Sox optioned RHP Tanner Houck to Worcester Red Sox. |
| 07/29/21 | Washington Nationals traded LF Kyle Schwarber to Boston Red Sox for RHP Aldo Ramirez. |
| 07/29/21 | Washington Nationals traded LF Kyle Schwarber to Boston Red Sox for RHP Aldo Ramirez. |
| 07/29/21 | Boston Red Sox designated RHP Brandon Workman for assignment. |
| 07/28/21 | Boston Red Sox signed free agent LHP Anddy Flores to a minor league contract. |
| 07/28/21 | Boston Red Sox recalled C Connor Wong from Worcester Red Sox. |
| 07/27/21 | Boston Red Sox sent RHP Hirokazu Sawamura on a rehab assignment to Worcester Red Sox. |
| 07/26/21 | Boston Red Sox signed free agent RHP Yonfi Rodriguez to a minor league contract. |
| 07/24/21 | Boston Red Sox signed free agent OF Ronny Ramirez to a minor league contract. |
| 07/24/21 | Boston Red Sox signed SS Daniel McElveny. |
| 07/24/21 | Boston Red Sox signed RHP Christopher Troye. |
| 07/24/21 | Boston Red Sox signed RHP Hunter Dobbins. |
| 07/24/21 | Boston Red Sox signed RHP Wyatt Olds. |
| 07/24/21 | Boston Red Sox signed 3B Tyler Miller. |
| 07/24/21 | Boston Red Sox signed free agent RHP Jhonny Felix to a minor league contract. |
| 07/24/21 | Boston Red Sox signed RHP Jacob Webb. |
| 07/24/21 | Boston Red Sox signed RHP Tyler Uberstine. |
| 07/24/21 | Boston Red Sox signed RHP Elmer Rodriguez-Cruz. |
| 07/24/21 | Boston Red Sox signed 2B B.J. Vela. |
| 07/24/21 | Boston Red Sox signed OF Phillip Sikes. |
| 07/24/21 | Boston Red Sox signed free agent OF Kier Meredith to a minor league contract. |
| 07/23/21 | Boston Red Sox placed RHP Hirokazu Sawamura on the 10-day injured list. Right triceps inflammation. |
| 07/23/21 | Boston Red Sox recalled RHP Phillips Valdez from Worcester Red Sox. |
| 07/22/21 | Boston Red Sox placed SS Danny Santana on the 10-day injured list. Left groin strain. |
| 07/22/21 | Boston Red Sox recalled CF Franchy Cordero from Worcester Red Sox. |
| 07/22/21 | Boston Red Sox signed SS Marcelo Mayer. |
| 07/22/21 | Boston Red Sox signed 2B Tyler McDonough. |
| 07/20/21 | Boston Red Sox sent LHP Chris Sale on a rehab assignment to Portland Sea Dogs. |
| 07/19/21 | Boston Red Sox placed 3B Christian Arroyo on the 10-day injured list. Left hamstring strain. |
| 07/19/21 | Boston Red Sox activated SS Danny Santana. |
| 07/17/21 | Philadelphia Phillies traded RHP Victor Santos to Boston Red Sox. |
| 07/17/21 | Boston Red Sox sent RHP Austin Brice outright to Worcester Red Sox. |
| 07/16/21 | Boston Red Sox sent SS Danny Santana on a rehab assignment to Worcester Red Sox. |
| 07/16/21 | Boston Red Sox placed SS Marwin Gonzalez on the 10-day injured list. Right hamstring strain. |
| 07/16/21 | Boston Red Sox selected the contract of 2B Jarren Duran from Worcester Red Sox. |
| 07/16/21 | Boston Red Sox designated RHP Austin Brice for assignment. |
| 07/16/21 | Boston Red Sox recalled RHP Tanner Houck from Worcester Red Sox. |
| 07/15/21 | Boston Red Sox signed RHP Matt Litwicki. |
| 07/15/21 | Boston Red Sox sent LHP Chris Sale on a rehab assignment to FCL Red Sox. |
| 07/10/21 | Boston Red Sox placed RHP Matt Andriese on the 10-day injured list. Right hamstring tendinitis. |
| 07/10/21 | Boston Red Sox selected the contract of RHP Austin Brice from Worcester Red Sox. |
| 07/09/21 | Boston Red Sox recalled 2B Michael Chavis from Worcester Red Sox. |
| 07/09/21 | Boston Red Sox placed SS Danny Santana on the 10-day injured list. Left quad strain. |
| 07/09/21 | Boston Red Sox activated C Kevin Plawecki from the 10-day injured list. |
| 07/08/21 | Boston Red Sox optioned C Connor Wong to Worcester Red Sox. |
| 07/07/21 | Boston Red Sox signed free agent RHP Eybersson Polanco to a minor league contract. |
| 07/05/21 | Boston Red Sox recalled RHP Eduard Bazardo from Worcester Red Sox. |
| 07/05/21 | Boston Red Sox activated 3B Christian Arroyo. |
| 07/05/21 | Boston Red Sox optioned 2B Michael Chavis to Worcester Red Sox. |
| 07/05/21 | Boston Red Sox placed RHP Eduard Bazardo on the 60-day injured list. Right lat strain. |
| 07/02/21 | Boston Red Sox signed free agent LHP Bryant Nunez to a minor league contract. |
| 07/02/21 | Boston Red Sox signed free agent 3B Andy Lugo to a minor league contract. |
| 07/01/21 | Boston Red Sox sent 3B Christian Arroyo on a rehab assignment to Worcester Red Sox. |