Carter Alswinn Kieboom (born September 3, 1997) is an American professional baseball third baseman for the Washington Nationals of Major League Baseball (MLB).
Kieboom announced he would be signing with the Nationals and joining the organization on June 11, 2016. He spent his first professional season with the Gulf Coast League Nationals where he batted .244 with four home runs and 25 RBIs.
In 2017 with the Class-A Hagerstown Suns, he was hitting .333 and six home runs and 20 RBIs before a hamstring injury on May 12 placed him on the disabled list.
Kieboom began the 2019 season with the Fresno Grizzlies of the Class AAA Pacific Coast League. On April 26, 2019, the Nationals purchased Kieboom’s contract and promoted him to the major league roster for a series against the San Diego Padres. He made his debut that night and hit a home run for his first major league hit.
Following the departure of veteran third baseman Anthony Rendon after the 2019 season, Nationals manager Dave Martinez said in January 2020 that Kieboom would move to third base full time, with the expectation that he would step in as Rendon’s permanent replacement in the 2020 season.
In 2020 for the Nationals, Kieboom played in 33 games, hitting .202/.344/.212 with no home runs and 9 RBI before ending his season early due to a left wrist contusion.