The 2004 National League Championship Series (CS) was a Major League Baseball playoff series played from October 13 to 21 to determine the champion of the National League, between the Central Division champion St. Louis Cardinals and the wild-card qualifying Houston Astros. This marked the first time in either Major League that two teams from the Central Division met in a Championship Series.
In a series in which all seven games were won by the home team, the Cardinals won 4–3 to advance to the World Series against the American League champion Boston Red Sox. The Red Sox reached their first World Series since 1986, with the Cardinals playing in their first since 1987. While the CS was an exciting back-and-forth series, it was overshadowed in media attention by Boston's comeback in the CS.