The 2019 Washington Nationals season was the Nationals' 15th season competing as the Major League Baseball (MLB) franchise representative in the District of Columbia, the 12th season at Nationals Park, and the 51st since the original team was started in Montreal, Quebec, Canada. The team clinched a playoff berth for the third time in four seasons on September 24. The Nationals won their first ever National League pennant on October 15, and eventually won their first World Series in franchise history on October 30, becoming the seventh Wild Card team to win the World Series. The Nationals also set all-time franchise records in home runs (231) and runs scored (873).
The Nationals began their regular season at home against the New York Mets on March 28 and ended their regular season at home against the Cleveland Indians on September 29. They beat the Milwaukee Brewers in the Wild Card Game on October 1 and upset the two-time defending National League champions and 106 game winning Los Angeles Dodgers in five games in the Division Series, before advancing to the National League Championship Series for the first time since 1981, where they swept the St. Louis Cardinals. They won the pennant and advanced to the World Series for the first time in Nationals franchise history. This was also Washington, D.C.'s first appearance in the World Series since the American League's Senators in 1933. They proceeded to defeat the Houston Astros in seven games to capture the franchise's first World Series championship, and the first for Washington, D.C. since 1924. The Nationals also became just the second team to sweep their opponent in the League Championship Series since going to a best-of-seven format, and subsequently go on to win the World Series, the other team being the 1995 Atlanta Braves, and the first team in North American professional sports to win all road games in a best-of-seven playoff series when they prevailed over the Astros.
As of 2022, this represents the most recent winning season and playoff berth for the Nationals.
Offseason
Team news
With the Washington Nationals coming off a disappointing 82–80 2018 season, general manager and president of baseball operations Mike Rizzo nonetheless declared confidence in manager Dave Martinez and his coaching staff, all under contract for the 2019 season.
The Nationals' player development contract with the Class-AAA Syracuse Chiefs expired following the 2018 minor league season. Instead, the Nationals signed a two-year player development contract with the Fresno Grizzlies of the Pacific Coast League, although Rizzo publicly acknowledged Fresno was team officials' "second choice" behind the Nashville Sounds, who signed a four-year deal with the Texas Rangers instead.
Set to become a free agent after the 2018 season, Bryce Harper indicated in numerous interviews and speaking appearances that he was interested in reaching a new deal with the Nationals, despite considerable media speculation that Washington would be unwilling to meet Harper's likely asking price for a contract. The Nationals made Harper what principal managing owner Mark Lerner later described as "one heck of an offer" in an attempt to extend him toward the end of the 2018 season, reported to be roughly $300 million over ten years, which would have been a record-setting amount for a free agent in American sports, but Harper elected free agency and Lerner said in December he expected him to sign for a higher bid elsewhere. Harper ultimately signed with the division-rival Philadelphia Phillies for a reported $330 million over 13 years, the largest free agent contract in the history of North American sports, after a pursuit that stretched into March. Along with Harper, starting pitcher Jeremy Hellickson, catcher Matt Wieters, infielder Mark Reynolds, and relievers Joaquín Benoit, Tim Collins, Kelvin Herrera, and Greg Holland became free agents after the 2018 season. Catcher Jhonatan Solano elected free agency as well after being outrighted from the roster. Hellickson signed a new one-year major league contract to stay in Washington for the 2019 season.