Won a silver medal with Team USA at the Tokyo 2020 Olympic Games, making two appearances out of the bullpen. He pitched 0.2 innings of relief against Korea in the Group B finale, striking out two batters and helping tie an Olympic team record for strikeouts in a game with 14. He also came on in extra-innings against Japan and suffered the tough loss, giving up the walk-off run.

Jackson went 1-0 with a 3.38 ERA in two appearances at the WBSC Baseball Americas Qualifier, including a 2.0-inning stint to earn the victory in the title game – a 4-2 win over Venezuela. He also worked two-thirds of an inning in relief to help Team USA to an 8-6 win over the Dominican Republic that clinched a spot in the AOQ Super Round.