Soto signed as an international free agent with the Nationals in 2015. He made his MLB debut in 2018 and finished second in the NL Rookie of the Year voting. In 2019,
He was an important part of the Nationals' first World Series victory. He won the National League batting title in 2020 with a.351 average.
Soto made his major-league debut on May 20, 2018, at the age of 19 years, 207 days, and became the first player born in 1998 to appear in a major-league game.
On June 21, he made his major league debut as the cleanup hitter against the Baltimore Orioles. In a 4-2 victory, he doubled home the winning run.
In 414 at-bats, Soto hit.292/.406/.517 with 79 walks (10th in the NL), 22 home runs, and 70 RBIs. He was the NL's youngest player at the time.
He was named NL Rookie of the Month in June, July, and September, making him the sixth player to win the award three times or more.
Following the season, Soto was named to the All-MLB First Team and won the National League Silver Slugger Award for the outfield for the second consecutive year.
Soto became the sixth player in MLB history to be named runner-up for both MVP and Rookie of the Year.
Soto reportedly rejected a 15-year, $440 million contract extension offer by the Nationals during the 2022 season.