The 2018 National League Division Series were two best-of-five-game series on the National League side in Major League Baseball’s 2018 postseason to determine the participating teams of the 2018 National League Championship Series. The three divisional winners (seeded 1–3) and a fourth team—the Wild Card Game winner—played in two series. These matchups were:

The Dodgers defeated the Brewers in the NLCS, then lost the 2018 World Series to the American League champion Boston Red Sox.

Under sponsorship agreements with Doosan, the series was formally known as the National League Division Series presented by Doosan. The Brewers and the Dodgers won their respective series to advance to the Championship Series.

The 2018 National League division races were unexpectedly surprising, considering the Nationals, Cubs, and Dodgers all came into the season as heavy betting favorites, and on the last day of the season, none of these teams had an outright lead in their division. The Brewers entered the NLDS as the top seed, having completed the regular season with a record of 96–67 and winning the NL Central via a tie-breaker game. The second-seeded Dodgers went 92–71 in the NL West, also winning their division via a tie-breaker game. The NL East champion Braves were seeded third via their 90–72 record. The final participant was the winner of the NL Wild Card Game, the Rockies. This was the first year in baseball history two divisions in the same league came down to a Game 163.

This was the 14th NLDS appearance for Atlanta, 13th for Los Angeles, fourth for Colorado and third for Milwaukee (who also played in the 1981 ALDS, before joining the National League in 1998).

The Brewers and Rockies met seven times during the regular season, with Milwaukee winning five of the games. The Dodgers and Braves also met seven times during the regular season, with Los Angeles holding a 5–2 edge.

Milwaukee won the series, 3–0.

Los Angeles won the series, 3–1.