American League

1. Seattle Mariners – AL West champions, 116–46^[2]
2. New York Yankees – AL East champions, 95–65^[3]
3. Cleveland Indians – AL Central champions, 91–71^[4]
4. Oakland Athletics – 102–60^[5]

National League

1. Houston Astros – NL Central champions, 93–69 (9–7 head-to-head vs. STL)^[6]
2. Arizona Diamondbacks – NL West champions, 92–70^[7]
3. Atlanta Braves – NL East champions, 88–74^[8]
4. St. Louis Cardinals – 93–69 (7–9 head-to-head vs. HOU)^[9]

(1) Seattle Mariners vs. (3) Cleveland Indians

Seattle won the series, 3–2.

This was the second postseason meeting between the Mariners and Indians, they had previously met in the 1995 ALCS which the Indians won in six games en route to the World Series. The Mariners narrowly defeated the Indians in five games to return to the ALCS for the second year in a row.

The Indians shocked the Mariners with a 5-0 shutout win in Game 1 in Seattle. The Mariners won Game 2 by a 5-1 score to even the series going into Cleveland. In Game 3, the Indians blew out the Mariners 17-2, handing Seattle its worst postseason loss ever. Going into Game 4, Cleveland looked poised to complete a historic upset; however, the Mariners would prevail by a 6-2 score to force a series-deciding Game 5 at Safeco Field. The Mariners managed to win Game 5 and advance to the ALCS.

This was the most recent playoff win for Seattle until 2022, where they swept the Toronto Blue Jays in the Wild Card series. This was the last postseason appearance for the Indians until 2007.

(2) New York Yankees vs. (4) Oakland Athletics

New York won the series, 3–2.

In a rematch of the previous year's ALDS, the Yankees rallied from a 2-0 series deficit to once again defeat the Athletics in five games, returning to the ALCS for the fifth time in the past six seasons.

The Athletics took Games 1 and 2 in the Bronx, and looked poised to eliminate the Yankees. However, when the series moved to Oakland, the Yankees took Game 3 in a 1-0 shutout, and then blew out the Athletics in Game 4 to even the series. Game 5 of this ALDS was memorable for a play by Derek Jeter in the top of the eighth inning. During that inning, Oakland's Terrance Long hit a towering foul pop up in a two-run game. Jeter then went after the ball making a backhanded grab, and then turning his body, flipped into the stands. For a moment, no one knew if the ball had been caught, but it was eventually confirmed. The Yankees took Game 5 by a 5-3 score, and returned to the ALCS.

The Athletics would make their next postseason appearance in 2003, where they lost to the Boston Red Sox in five games in the ALDS after blowing another series lead.

Game 5 of the 2001 ALDS is shown in the opening scene of the 2011 film Moneyball. The film shows Johnny Damon's first inning leadoff double followed by Jason Giambi’s RBI single. Then, the defensive miscues by Oakland are shown as three errors were committed. The final out of the game (Eric Byrnes striking out) is used as a transition point from the game footage to the actual beginning of the film.

(1) Houston Astros vs. (3) Atlanta Braves

Atlanta won the series, 3–0.

In the third postseason meeting between these two teams, the Braves swept the top-seeded Astros to return to the NLCS for the ninth time in eleven years. This series was not close - the Braves took Game 1 in Houston by a 7-4 score, and then won Game 2 in a 1-0 shutout to go up 2-0 in the series heading back to Atlanta. The Braves put away the Astros in Game 3 by a 6-2 score to advance to the NLCS.

The Braves and Astros would meet again in the NLDS two more times - in 2004 and 2005, which were both won by the Astros.

(2) Arizona Diamondbacks vs. (4) St. Louis Cardinals

Arizona won the series, 3–2.

This was the first postseason meeting between the Diamondbacks and Cardinals. The Diamondbacks prevailed in a back-and-forth five game series to advance to the NLCS for the first time in franchise history.

Curt Schilling pitched a three-hit complete game shutout for the Diamondbacks in Game 1, while the Cardinals won Game 2 by a 4-1 score to even the series and gain the home field advantage. In St. Louis, the Diamondbacks rallied late to win Game 3 and regain the series lead, while the Cardinals took Game 4 in another 4-1 victory to send the series back to Phoenix for Game 5. Schilling once again helped the Diamondbacks narrowly defeat the Cardinals in Game 5, ans they won by a 2-1 score to advance to the NLCS.

Both the Cardinals and Diamondbacks would meet again in the NLDS the following year, with the Cardinals winning in a sweep.

(1) Seattle Mariners vs. (2) New York Yankees

New York won the series, 4–1.

In the third postseason meeting between these two teams, the Yankees upset the 116-win Mariners to advance to the World Series for the fifth time in six years. The series was lopsided in favor of the Yankees - the Yankees took the first two games in Seattle. When the series moved to the Bronx, the Mariners blew out the Yankees in Game 3 to avoid a sweep. However, the Yankees would win Game 4, and then proceeded to blow out the Mariners in Game 5 to secure the pennant. With the win, the Yankees improved their record against the Mariners to 2-1 all time.

After the series loss, the Mariners entered a slump, and held the longest postseason appearance drought in North American sports. They would not return to the postseason again until 2022. The Yankees would win their next AL pennant in 2003 over their archrival in the Boston Red Sox in seven games.

(2) Arizona Diamondbacks vs. (3) Atlanta Braves

Arizona won the series, 4–1.

The Diamondbacks defeated the Braves in five games to advance to the World Series for the first time in franchise history.

The teams split the first two games in Phoenix - the Diamondbacks took Game 1 by a 2-0 score thanks to a three-hit complete game shutout by Randy Johnson, who out-dueled Greg Maddux, while the Braves blew out the Diamondbacks in Game 2 thanks to a lights out performance from Tom Glavine to even the series. When the series moved to Atlanta, the Diamondbacks won Game 3 by a 5-1 score as Curt Schilling pitched yet another complete game. The Diamondbacks then blew out the Braves by seven runs in Game 4 to take a 3-1 series lead. In Game 5, Byung-hyun Kim held off a late rally by the Braves as the Diamondbacks held on to win and secure their first NL pennant.

The Diamondbacks would return to the NLCS in 2007, but were swept by the Colorado Rockies, who made a Cinderella run to the World Series. They would not win the NL pennant again until 2023, where they defeated the Philadelphia Phillies in seven games after trailing 2-0 and 3-2 in the series.

This was the last time the Braves appeared in the NLCS until 2020, where they fell to the Los Angeles Dodgers in seven games after leading the series three games to one.

(AL2) New York Yankees vs. (NL2) Arizona Diamondbacks

Arizona won the series, 4–3.

This was the first World Series ever played in the Mountain West region. In what is considered by many to be one of the greatest World Series ever played, the Diamondbacks shocked the Yankees in seven games to win their first championship in franchise history, denying the Yankees a fourth straight title.

The first two games were dominated by Arizona, as they blew out the Yankees in Game 1, and won Game 2 in a shutout. When the series moved to the Bronx, the Yankees narrowly took Game 3 to avoid a sweep. Then, the Yankees won Games 4 and 5, both in extra innings, due to two blown saves from Arizona's Byung-hyun Kim. The Yankees were now one win away from a fourth straight title. However, when the series moved back to Phoenix for Game 6, the Diamondbacks blew out the Yankees 15-2 to force a Game 7, handing the Yankees what was their worst postseason loss in franchise history until 2018. Game 7 was the most memorable contest of the series - the Diamondbacks scored first in the bottom of the sixth to go up 1-0. Then the Yankees scored two unanswered runs in the top of the seventh and eighth innings to take the lead. In the bottom of the ninth, the Yankees were two outs away from securing the title, however the Diamondbacks tied the game at two runs each, handing Yankees closer Mariano Rivera his first blown save in four years. The series then ended with a walk-off, bases-loaded bloop single by Luis Gonzalez to clinch the title for Arizona. This was the first World Series since 1991 in which neither team won a game on the road.

This was the first (and only) championship of the four major North American sports leagues won by a team from the Phoenix metropolitan area. The NBA’s Phoenix Suns reached the NBA Finals three times in their history - 1976, 1993, and 2021, but lost each time in six games. The NFL’s Arizona Cardinals reached the Super Bowl in 2009, but narrowly lost to the Pittsburgh Steelers. As of 2023, no other professional sports team from Phoenix has won a championship.

The Diamondbacks would return to the postseason the next year in hopes of defending their title, but were swept by the St. Louis Cardinals in the NLDS. They returned to the NLCS in 2007, but were swept by the Colorado Rockies, who made a Cinderella run to the World Series. They would make their next World Series appearance in 2023, but they would lose to the Texas Rangers in five games.

The Yankees hoped to earn a shot a redemption the following year, but were upset by the eventual World Series champion Anaheim Angels in the ALDS. They would return to the World Series in 2003, but were defeated by the Florida Marlins in six games. They would win their next championship in 2009, against the Philadelphia Phillies in six games.