January 13, 2020

January 14, 2020

Athletics  sign Jared Koenig

February 15, 2020

Athletics  place Daniel Mengden on the injured list

Burch Smith traded from Giants  to Athletics 

June 30, 2020

Jorge Mateo traded from Athletics  to Padres 

July 22, 2020

Athletics  place A.J. Puk on the injured list

August 04, 2020

Athletics  place Jordan Weems on the injured list

August 07, 2020

Mark Payton traded from Athletics  to Reds 

August 16, 2020

Athletics  place Burch Smith on the injured list

August 29, 2020

Tommy La Stella traded from Angels  to Athletics 

August 31, 2020

Mike Minor traded from Rangers  to Athletics 

September 02, 2020

Athletics  place Daniel Mengden on the injured list

September 12, 2020

Athletics  place Matt Chapman on the injured list

September 13, 2020

Athletics  place Chad Pinder on the injured list

September 14, 2020

Athletics  sign Jake Lamb as a free agent

September 20, 2020

Athletics  designate Daniel Mengden for assignment

September 24, 2020

Athletics  place J.B. Wendelken on the injured list

October 28, 2020

Tommy La Stella became a free agent

Jake Lamb became a free agent

Marcus Semien became a free agent

Liam Hendriks became a free agent

Yusmeiro Petit became a free agent

T.J. McFarland became a free agent

Robbie Grossman became a free agent

Mike Minor became a free agent

Joakim Soria became a free agent

Mike Fiers became a free agent

November 12, 2020

Athletics  sign Jacob Wilson as a free agent

November 16, 2020

Athletics  sign Domingo Acevedo as a free agent

November 17, 2020

Athletics  sign Frank Schwindel

Athletics  sign Pete Kozma as a free agent

December 14, 2020

Athletics  sign Reymin Guduan