The 2004 World Series was the championship series of Major League Baseball's (MLB) 2004 season. The 100th edition of the World Series, it was a best-of-seven playoff between the American League (AL) champion Boston Red Sox and the National League (NL) champion St. Louis Cardinals; the Red Sox swept the Cardinals in four games. The series was played from October 23 to 27, 2004, at Fenway Park and Busch Memorial Stadium, broadcast on Fox, and watched by an average of just under 25.5 million viewers. The Red Sox's World Series championship was their first since 1918.