January 04, 2021

Red Sox  sign Zack Kelly

January 16, 2021

Red Sox  sign Jack Lopez

January 25, 2021

February 02, 2021

Red Sox  sign Enrique Hernandez as a free agent

February 03, 2021

Red Sox  designate Joel Payamps for assignment

Red Sox  sign Garrett Richards as a free agent

February 10, 2021

February 12, 2021

Red Sox  designate Chris Mazza for assignment

Red Sox  sign Martin Perez as a free agent

February 16, 2021

Red Sox  designate Jeffrey Springs for assignment

Red Sox  sign Hirokazu Sawamura as a free agent

February 17, 2021

Red Sox  place Kevin Plawecki on the injured list

February 18, 2021

Red Sox  place Chris Sale on the injured list

February 22, 2021

Red Sox  place Franchy Cordero on the injured list

February 24, 2021

Red Sox  sign Marwin Gonzalez as a free agent

March 07, 2021

Red Sox  sign Danny Santana as a free agent

March 30, 2021

Red Sox  designate John Schreiber for assignment

April 01, 2021

Red Sox  place Ryan Brasier on the injured list

Red Sox  place Eduardo Rodriguez on the injured list

April 10, 2021

Red Sox  place J.D. Martinez on the injured list

May 03, 2021

Red Sox  place Ryan Brasier on the injured list

May 06, 2021

Red Sox  sign Brandon Workman

May 07, 2021

Red Sox  place Enrique Hernandez on the injured list

May 09, 2021

Red Sox  place Christian Arroyo on the injured list

May 12, 2021

Red Sox  place Nick Pivetta on the injured list

May 15, 2021

Red Sox  place Garrett Whitlock on the injured list

May 21, 2021

Red Sox  designate Austin Brice for assignment

June 03, 2021

Red Sox  designate Colten Brewer for assignment

June 13, 2021

Red Sox  designate Brandon Brennan for assignment

June 14, 2021

Red Sox  designate Ryan Weber for assignment

Yacksel Rios traded from Mariners  to Red Sox 

June 22, 2021

Red Sox  place Kevin Plawecki on the injured list

June 24, 2021

Red Sox  place Christian Arroyo on the injured list

July 05, 2021

Red Sox  place Eduard Bazardo on the injured list

July 09, 2021

Red Sox  place Danny Santana on the injured list

July 10, 2021

Red Sox  place Matt Andriese on the injured list

July 16, 2021

Red Sox  place Marwin Gonzalez on the injured list

Red Sox  designate Austin Brice for assignment

July 19, 2021

Red Sox  place Christian Arroyo on the injured list

July 22, 2021

Red Sox  place Danny Santana on the injured list

July 23, 2021

Red Sox  place Hirokazu Sawamura on the injured list

July 29, 2021

Red Sox  designate Brandon Workman for assignment

Kyle Schwarber traded from Nationals  to Red Sox 

July 30, 2021

Red Sox  designate Marcus Wilson for assignment

Hansel Robles traded from Twins  to Red Sox 

July 31, 2021

Red Sox  place Darwinzon Hernandez on the injured list

August 03, 2021

Red Sox  place Matt Barnes on the injured list

August 04, 2021

Delino DeShields traded from Rangers  to Red Sox 

Red Sox  sign Jose De Leon

August 06, 2021

Red Sox  place Jarren Duran on the injured list

August 07, 2021

Red Sox  place J.D. Martinez on the injured list

August 10, 2021

Red Sox  sign Alex Claudio

August 13, 2021

Red Sox  designate Marwin Gonzalez for assignment

August 15, 2021

Red Sox  place Josh Taylor on the injured list

August 16, 2021

Red Sox  release Marwin Gonzalez

August 17, 2021

Red Sox  designate Matt Andriese for assignment

August 19, 2021

Red Sox  release Matt Andriese

August 27, 2021

Red Sox  place Enrique Hernandez on the injured list

Red Sox  place Christian Arroyo on the injured list

August 28, 2021

Red Sox  sign Michael Feliz

August 30, 2021

Red Sox  place Martin Perez on the injured list

Red Sox  place Matt Barnes on the injured list

Brad Peacock traded from Indians  to Red Sox 

August 31, 2021

Red Sox  place Josh Taylor on the injured list

Red Sox  place Hirokazu Sawamura on the injured list

Delino DeShields traded from Red Sox  to Reds 

September 01, 2021

Red Sox  place Yairo Munoz on the injured list

Red Sox  place Xander Bogaerts on the injured list

September 03, 2021

Red Sox  place Jarren Duran on the injured list

September 05, 2021

Red Sox  place Nick Pivetta on the injured list

Red Sox  place Danny Santana on the injured list

September 06, 2021

Red Sox  sign Jose Iglesias as a free agent

September 07, 2021

Red Sox  designate Taylor Motter for assignment

September 10, 2021

Red Sox  place Chris Sale on the injured list

Red Sox  place Jonathan Arauz on the injured list

September 11, 2021

Red Sox  place Danny Santana on the injured list

September 12, 2021

Red Sox  place Phillips Valdez on the injured list

September 17, 2021

Red Sox  designate Michael Feliz for assignment

September 21, 2021

Red Sox  place Garrett Whitlock on the injured list

September 23, 2021

Red Sox  designate Geoff Hartlieb for assignment

Red Sox  designate Yacksel Rios for assignment

September 26, 2021

Red Sox  place Josh Taylor on the injured list

October 08, 2021

Red Sox  place Garrett Richards on the injured list

October 21, 2021

Red Sox  designate Franchy Cordero for assignment

November 03, 2021

Hansel Robles became a free agent

Adam Ottavino became a free agent

Eduardo Rodriguez became a free agent

Danny Santana became a free agent

Travis Shaw became a free agent

November 04, 2021

Kyle Schwarber became a free agent

November 07, 2021

Martin Perez became a free agent

Garrett Richards became a free agent

November 27, 2021

Red Sox  sign Michael Wacha as a free agent

November 30, 2021

Tim Locastro became a free agent

December 01, 2021

Red Sox  sign Rich Hill as a free agent

Red Sox  sign James Paxton as a free agent

Red Sox  sign Michael Feliz

December 21, 2021

Red Sox  sign Rob Refsnyder