Jhon Jairo Romero (born January 17, 1995) is a Colombian professional baseball pitcher who is a free agent.

Older than most international amateurs when he joined a professional baseball organization, Romero was 20 years old when the Chicago Cubs signed him out of Colombia in 2015 and assigned him to their Dominican Summer League affiliate.

[3] Promoted to the Myrtle Beach Pelicans in the Advanced-A Carolina League to begin the 2018 season, Romero posted a 3.27 ERA and 1.30 WHIP over 32 appearances through July.

[5] Although effective finishing out the year with the Potomac Nationals, Washington's High-A affiliate, Romero struggled in 2019 and was ultimately diagnosed with a torn ulnar collateral ligament of the elbow in his right throwing arm.

He underwent Tommy John surgery to replace the damaged ligament, missing the remainder of the 2019 season and not playing in 2020 due to the COVID-19 pandemic.

[8] Romero made his major league debut the following day against the Cincinnati Reds, pitching a scoreless inning of relief.