In the National League, the Los Angeles Dodgers clinched their eleventh straight postseason berth, which is currently the longest active streak in the majors and in professional sports.

The only division winner to advance to the League Championship Series were the Houston Astros (AL West), following the defeat of the Milwaukee Brewers (NL Central) by the Arizona Diamondbacks in a sweep, in the Wild Card Series, then the defeats of the Minnesota Twins (AL Central) by the Houston Astros in four games, Baltimore Orioles (AL East) by the Texas Rangers in a sweep, Los Angeles Dodgers (NL West) by the Arizona Diamondbacks in a sweep, and the Atlanta Braves (NL East) by the Philadelphia Phillies in four games, in the Division Series.

[3] The postseason began on October 3 and ended on November 1, with the Rangers defeating the Diamondbacks in the 2023 World Series to clinch their first title in franchise history.

All five of the teams with artificial turf in the major leagues reached the postseason: Miami, Arizona, Toronto, Tampa Bay, and Texas.

In Game 2, Sonny Gray out-dueled the Blue Jays' José Berríos and Yusei Kikuchi as the Twins won in a 2–0 shutout to win their first playoff series in 21 years.

[39] Nathan Eovaldi pitched a solid 62⁄3 innings in Game 2 as the Rangers blew out the Rays by a 7–1 score to complete the sweep and advance.

In Game 2, the Brewers again jumped out to an early lead and had a no-hit bid going into the top of the fifth, until Arizona's Alek Thomas hit a solo home run to end it.

Then the Diamondbacks rallied to win again, as Carroll doubled and Marte hit a two-RBI single to put Arizona in the lead, and then a wild pitch and then a blooper scored the next two runs.

Aaron Nola pitched seven strong innings in Game 2 as the Phillies blew out the Marlins by a 7–1 score, capped off by Bryson Stott's grand slam in the bottom of the sixth.

The Rangers held off a late push by the Orioles to take Game 1 on the road, capped off by Josh Jung's solo home run in the top of the sixth.

Game 2 was an offensive slugfest which the Rangers won 11–8, in part thanks to a third-inning grand slam hit by Mitch Garver.

Nathan Eovaldi pitched seven solid innings in Game 3 as the Rangers blew out the Orioles by a 7–1 score to complete the sweep.

Game 1 was notable for Justin Verlander's six shutout innings pitched for the sixth scoreless start of his postseason career, tying Madison Bumgarner and Tom Glavine for most all-time.

[52] In Game 2, Pablo López pitched seven solid innings for the Twins, as they jumped out to a big lead early and didn't relinquish it, winning 6–2 to even the series headed to Minneapolis.

[53] Cristian Javier pitched five scoreless innings in Game 3 as the Astros blew out the Twins by a 9–1 score to regain the series lead.

In Game 2, the Braves overcame a late deficit in the seventh and eighth innings to even the series, thanks to a pair of two-run home runs from Travis d'Arnaud and Austin Riley.

The Phillies blew out the Braves by a 10–2 score in Game 3, thanks to multiple home runs from Nick Castellanos, Bryce Harper, Trea Turner, and Brandon Marsh.

In a significant upset given their regular season win differential, the 84-win Diamondbacks swept the 100-win Dodgers, reaching the NLCS for the first time since 2007.

The Diamondbacks jumped out to a big lead in the top of the first, as their first five batters scored, highlighted by a three-run home run from Gabriel Moreno.

The Dodgers' ace Clayton Kershaw was pulled after giving up an RBI double to Evan Longoria, which extended Arizona's lead to 6–0.

In Game 2, the Diamondbacks again jumped out to a big early lead and held off a late rally by the Dodgers to win 4–2, capped off by an insurance home run by Lourdes Gurriel Jr. in the top of the sixth.

When the series shifted to Phoenix, the Diamondbacks once again jumped out to a 4–0 lead early, thanks to four solo home runs from Moreno, Geraldo Perdomo, Ketel Marte, and Christian Walker respectively.

In the Rangers' first-ever ALCS Game 7, García once again took center stage, as he along with Corey Seager and Nathaniel Lowe blew out the Astros again and secured the pennant.

They also became the second fifth-seeded team in MLB history to reach the World Series, joining the 2014 San Francisco Giants, who were also managed by Bruce Bochy.

In Game 1, the Phillies chased Arizona starter Zac Gallen from the mound early, and held off a late rally by the Diamondbacks to win 5–3.

However, the Phillies regained the series lead in Game 5 with a 6–1 victory as Zach Wheeler pitched seven solid innings, giving up only one earned run.

Marcus Semien’s RBI single and another two-run home run from Seager carried the Rangers to victory in Game 3 to regain the series lead.

Mitch Garver drove in Seager with an RBI single to put the Rangers in the lead for good, which was then capped off by a series-sealing two-run home run in the ninth by Semien off closer Paul Sewald.

The Rangers became the second fifth-seeded team to win the World Series, joining the 2014 San Francisco Giants, who were also managed by Bruce Bochy.

[84] TruTV simulcasted all games in the NLDS and aired a Hispanic focused alternative telecast of the NLCS called Peloteros.