Justin Robert Topa was born on March 7, 1991, he is an American professional baseball pitcher for the Milwaukee Brewers of Major League Baseball. He is 6 feet 4 inches tall. He made his MLB debut in 2020.
Topa was drafted in the 17th round, 509th overall, of the 2013 Major League Baseball Draft by the Pittsburgh Pirates. He signed with the team on June 13, 2013, and made his professional debut with the Jamestown Jammers of the NY-Penn League on June 18, 2013, in relief at the Mahoning Valley Scrappers pitching one inning, allowing one hit, and striking out one.
Topa finished the season with a 5–2 win-loss record and a 2.19 earned run average (ERA). Topa spent 2014 with the West Virginia Power, before receiving a promotion in 2015 to the Bradenton Marauders, with whom he would play through the 2016 season. Topa was released by the Pirates organization on April 1, 2017.
On June 17, 2018, Topa signed a minor league contract with the Texas Rangers organization. He spent the majority of the season with the Frisco RoughRiders and also appeared with the Down East Wood Ducks before he elected free agency on November 2, 2018.
On March 28, 2019, Topa signed a minor league contract with the Milwaukee Brewers organization. He spent the majority of the season with the Biloxi Shuckers and also played for the Carolina Mudcats.
On July 28, 2020, the Brewers added Topa to their 60-man player pool. Topa was called up to the majors for the first time on August 31, 2020, and made his debut that night against the Detroit Tigers.