The 1969 World Series was played between the New York Mets and the Baltimore Orioles, with the Mets prevailing in five games to accomplish one of the greatest upsets in Series history, as that particular Orioles squad was considered to be one of the finest ever (and still is by some baseball pundits). The World Series win earned the team the sobriquet "Miracle Mets", as they had risen from the depths of mediocrity (the 1969 team had the first winning record in Mets history).

The Mets became the first expansion team to win a division title, a pennant, and the World Series, winning in their eighth year of existence. Two teams would later surpass that, as the Florida Marlins won the 1997 World Series in their fifth year (also becoming the first wild card team to win a World Series) and the Arizona Diamondbacks won the 2001 World Series in their fourth year of play. This was the first World Series since 1954 to have games played in New York that didn't involve the New York Yankees; it was also the first World Series in which neither the New York Giants nor Brooklyn Dodgers (as both teams had moved to California in 1958) represented New York on the National League side.

The New York Mets, who had never finished higher than ninth place (next-to-last) nor won more than 73 games in a season since joining the National League in 1962, were not highly regarded before the 1969 season started. In fact, the best that could be said for them was that because the National League was being split into two divisions that year (as was the American League), the Mets were guaranteed to finish no lower than sixth place. The fact that the Mets began the season by losing 11–10 to the then-expansion Montreal Expos seemed to confirm this. With three weeks to go in the season, the underdog Mets stormed past the Chicago Cubs, who had led the Eastern Division for most of the season, winning 38 of their final 49 games for a total of 100 wins and capturing their first National League Eastern Division crown. Third-year pitcher Tom Seaver won a major-league-leading 25 games en route to his first Cy Young Award; the other two top Mets starting pitchers, Jerry Koosman and rookie Gary Gentry, combined to win 30 more games. Outfielder Cleon Jones hit a (then) club-record .340 and finished third in the National League batting race, while his lifelong friend and outfield mate Tommie Agee hit 26 home runs and drove in 76 runs to lead the club; they were the only players on the team who garnered more than 400 at bats. Manager Gil Hodges employed a skillful platoon system not unlike the Yankees of the Casey Stengel era, in which Ron Swoboda and Art Shamsky became a switch-hitting right fielder who hit 23 home runs and drove in 100 runs, and Ed Kranepool and Donn Clendenon added up to a switch-hitting first baseman who hit 23 more homers and knocked in another 95 runs. Everyone on the bench knew what their role was in the platoon—nobody felt that they'd ever lost their jobs. Almost to a man, the 1969 Mets were united in their praise of their manager's skill. In the first League Championship Series, the normally light-hitting Mets, once again considered underdogs despite having a better regular-season record than their opponent, put on an uncharacteristic power display by scoring 27 runs in sweeping the favored Atlanta Braves in three games.

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