The 2004 American League Championship Series (ALCS) was a best-of-seven playoff series in the 2004 Major League Baseball season. It featured the New York Yankees and the Boston Red Sox. The Red Sox beat the Yankees in seven games. It was a rematch of the 2003 ALCS.
The Yankees won the first three games of the series. The Red Sox then won the next four to win the series. This was the first time a team won a best-of-seven playoff series after losing the first three games.
The Red Sox would go on to win the World Series against the St. Louis Cardinals in four games. It was the Red Sox's first World Series title since 1918.