| Tournament details | |
|---|---|
| Dates | September 30 – October 25, 2003[1] |
| Teams | 8 |
| Final positions | |
| Champions | Florida Marlins (2nd title) |
| Runner-up | New York Yankees (39th World Series appearance) |
| Tournament statistics | |
| MVP | Josh Beckett (FLA) |
The 2003 Major League Baseball postseason was the playoff tournament of Major League Baseball for the 2003 season. The winners of the League Division Series would move on to the League Championship Series to determine the pennant winners that face each other in the World Series. This was the first edition of the postseason where home-field advantage in the World Series was awarded to the league who won the MLB All-Star Game, a rule which lasted until 2016.
In the American League, the New York Yankees made their ninth straight postseason appearance, the Oakland Athletics made their fourth straight appearance, the Minnesota Twins made their second straight appearance, and the Boston Red Sox made their first postseason appearance of the new Millennium.
In the National League, the Atlanta Braves made their twelfth consecutive appearance in the postseason, the Florida Marlins and Chicago Cubs made their first postseason appearance of the new Millennium, and the San Francisco Giants returned for the third time in four years.
The postseason began on September 30, 2003, and ended on October 25, 2003, with the Marlins defeating the Yankees in six games in the 2003 World Series. It was the Marlins' second title in franchise history.