The 2009 National League Championship Series (NLCS) was a best-of-seven baseball game series pitting the Los Angeles Dodgers against the Philadelphia Phillies for the National League Championship and the right to represent the National League in the 2009 World Series. The Phillies defeated the Dodgers four games to one. Los Angeles, whose NL-best 95–67 record topped Philadelphia's 93–69 record, retained home-field advantage. The series, the 40th in league history, began on October 15 and finished on October 21. TBS carried the championship on television.

The National League Championship Series (NLCS), also known as the National League Pennant, is a best-of-seven playoff and one of two League Championship Series comprising the penultimate round of Major League Baseball's (MLB) postseason. It is contested by the winners of the two National League (NL) Division Series. The winner of the NLCS wins the NL pennant and advances to the World Series, MLB's championship series, to play the winner of the American League's (AL) Championship Series. The NLCS began in 1969 as a best-of-five playoff and used this format until 1985, when it changed to a best-of-seven format.