The 2020 Major League Baseball season began on July 23 and ended on September 27 with only 60 games amid the COVID-19 pandemic. The full 162-game regular season was planned to begin on March 26, but the pandemic caused Major League Baseball (MLB) to announce on March 12 that the remainder of spring training was canceled and that the start of the regular season would be delayed by at least two weeks. On March 16, MLB announced that the season would be postponed indefinitely, following recommendations from the Centers for Disease Control and Prevention (CDC) to restrict events of more than 50 people. This was the first time that MLB games had been put on hold since the 2001 season, when the season was paused for over a week after the September 11 attacks.

Spring training resumed on July 1 and was rebranded as "Summer Camp". On July 3, the All-Star Game was canceled because of the delay to the regular season. Dodger Stadium, which was set to host the game, went on to host the 2022 All-Star Game.

On July 18, the Canadian federal government denied permission for the Toronto Blue Jays to play their home games at Rogers Centre in 2020 on grounds that repeated cross-border trips by both the Blue Jays and their opponents would be a major risk due to the higher spikes in COVID-19 cases in the U.S. compared to those in Canada. The Blue Jays then chose to play their home games at Sahlen Field in Buffalo, home of their Triple-A affiliate Buffalo Bisons.

An expanded 16-team postseason tournament began on September 29, with games of all but the first round being played at neutral sites. The World Series began on October 20 at Globe Life Field in Arlington, and ended on October 27, with the Los Angeles Dodgers defeating the Tampa Bay Rays in six games to win their first title since 1988.

Schedule The 2020 schedule greatly differed from the normal 162-game schedule. In an effort to reduce travel, each team played only nine opponents during the regular season instead of the usual 19 or 20. Teams were scheduled to play 10 games against each of their four division opponents. The remaining 20 games of the 60-game schedule were interleague contests. To reduce travel, the interleague division match-ups were AL East vs NL East, AL Central vs NL Central, and AL West vs NL West. At 60 games, this was the shortest regular season since 1878.

Several international and neutral-site games originally scheduled for the season were canceled due to COVID-19: On March 19, the Mexico Series and Puerto Rico Series games were canceled; the former would have featured the San Diego Padres and the Arizona Diamondbacks at Mexico City's Estadio Alfredo Harp Helú, and the latter featuring the New York Mets and the Miami Marlins at Hiram Bithorn Stadium in San Juan. On April 1, MLB canceled the London Series, which would have featured the Chicago Cubs and the St. Louis Cardinals at London Stadium. On April 30, MLB canceled the MLB Little League Classic at BB&T Ballpark in Williamsport, Pennsylvania, coinciding with the Little League World Series, which was scheduled to be played on August 23 between the Boston Red Sox and Baltimore Orioles. This cancellation coincided with the cancellation of the 2020 Little League World Series. On August 3, MLB canceled MLB at Field of Dreams — a game that was scheduled to be played on August 13 between the St. Louis Cardinals and Chicago White Sox at a temporary 8,000-seat ballpark on the Dyersville, Iowa farm site of the 1989 sports film Field of Dreams. The game was postponed to 2021.

March agreement between MLB and MLBPA On March 26, MLB and the Major League Baseball Players Association (MLBPA) reached an agreement on multiple considerations related to the start of the season being delayed, including: The 2020 MLB draft was to be held by July 20 and reduced from 40 rounds to five rounds. Player salaries were pro-rated, based on the length of the regular season. Players will receive full service time for the season, regardless of the length of the season Roster moves were frozen as of March 27, until the season began.

Possible schedules The indefinite delay of the season caused MLB to internally consider a number of scenarios for playing the season, as well as analysts suggesting ways it could be done. A shortened regular season, a season with many doubleheaders, and a postseason extending into late November with a World Series at an indoor or warm-weather neutral site were suggested.

In early April, Jeff Passan of ESPN reported that MLB was "increasingly focused on a plan that could allow them to start the season as early as May and has the support of high-ranking federal public health officials". The plan would have involved all 30 teams playing games with no fans in stadiums around the Phoenix metropolitan area, including Chase Field and spring training complexes. Players would have lived in isolation at local hotels.

Another report from USA Today baseball writer Bob Nightengale detailed another MLB proposal utilizing the Phoenix metro sites, but with the additional use of spring training sites in Florida, Marlins Park in Miami, and St. Petersburg's Tropicana Field. In addition, the 30 teams would be re-aligned for the season depending on their spring training sites into six divisions based upon their locations in Arizona and Florida and agnostic to the usual AL/NL demarcations and traditional geographic rivalries, effectively making the spring training Cactus League and Grapefruit League regular-season leagues.MLB considering radical realignment for 2020 season: Grapefruit and Cactus leagues , USA Today, Bob Nightengale, April 10, 2020. No interleague play would take place and the designated hitter rule would be utilized for all 30 teams, with the World Series occurring in November utilizing the larger MLB sites.

Disagreement over plans for a shortened season During May and June, MLB and Major League Baseball Players Association (MLBPA) were unable to agree on a specific plan for a shortened season.

In mid-May the MLB owners proposed a schedule of 82 games, to begin in July, with games to be played without fans in attendance. To minimize travel, teams would play only against other teams in their geographical division, plus interleague games against teams in the corresponding division of the other league. A team would play 13 games against each division rival and six games against each team in the other league's division. Postseason play would be expanded from 10 teams to 14, with each league fielding three division winners and four wild card teams. A designated hitter would be allowed in all games. Teams would have 30-man rosters available for each game. The proposal also outlined safety measures for health of players and staff and a modified compensation plan for players.

On June 1, the MLBPA countered with a 114-game proposal, with a regular season running from June 30 to October 31, a November postseason, giving players the right to opt-out of participating, a salary deferral plan in the event the postseason has to be canceled due to a second wave of the virus, and a $100 million advance during the second spring training, among others.

Owners then submitted a 76-game proposal to the players on June 8, with the regular season ending on September 27, the postseason ending in October, 75 percent prorated player salaries, and playoff pool money, among others. The MLBPA responded one day later with an 89-game plan with full prorated player salaries. The owners then sent a 72-game plan with 70 percent prorated player salaries, to which the MLBPA replied in a statement on June 13, "Further dialogue with the league would be futile. It's time to get back to work. Tell us when and where." However, the week of June 15 saw the owners propose a 60-game season while MLBPA counter with a 70-game season, which on June 19 was rejected by the owners.

Amid an increase in cases in Arizona and Florida, including positive cases among staff of the Phillies, and a Blue Jays player showing signs of symptoms, it was reported on June 19 that all spring training sites would be temporarily closed for deep cleaning, and all players would be required to test negative for COVID-19 before entering. It was then reported on June 20 that almost all MLB teams had elected to re-locate their training camps back to their home cities.

On June 22, hours after the MLBPA rejected the MLB's offer to play a 60-game season, MLB owners voted unanimously to impose the 60-game plan. By allowing the owners to unilaterally implement such a plan without the MLBPA, both sides retained the right to file a grievance against the other for not negotiating in good faith. On June 23, both sides agreed to health and safety protocols. Players reported to training camp July 1. Due to concerns related to the pandemic, several players chose not to play the season.

Revised 60-game schedule On July 6, MLB released the revised schedule for the shortened 60-game season. In the new schedule, teams played 10 games against each of their four divisional opponents in three series, with an unequal number of home games against each opponent. Each team had 20 home games for division opponents.

Interleague play comprised the other 20 games of the schedule, all against the division of the opposite league, temporarily suspending the yearly rotation of which divisions play each other. Like normal seasons in which corresponding interleague divisions play each other (e.g. 2018), teams played six games against their "natural rival" and three or four games against each of the other four teams in the division. However, for this year only, the Cleveland Indians were paired with the Pittsburgh Pirates instead of their normal rivals, the Cincinnati Reds, and the Detroit Tigers were paired with the Reds instead of the Pirates. This was done to reduce travel for all four teams.

The season started on July 23, with two games: New York Yankees at Washington Nationals and San Francisco Giants at Los Angeles Dodgers. The remaining 26 teams opened the season on July 24.

On July 23, MLB and MLBPA announced that the postseason would be an expanded 16-team playoff tournament for 2020 only, instead of the normal 10-team tournament. All first and second place teams in the six divisions would qualify for the playoffs. The final two spots in each league would go to the remaining teams with the best win–loss records. The teams in each league would be seeded by division winners (1–3), division runners-up (4–6), and best teams remaining (7–8). Seeding ties would be resolved by head-to-head record, intra-league record, and record in final 20 intra-league games, to remove the necessity for additional games. The first round of the playoffs would be a best-of-three series called the Wild Card Series, with all games to be played at the home of the higher seeded team. After that, the postseason would follow the usual pattern of five-game Division series, seven-game League Championship Series, and a seven-game World Series.

Postponed games COVID-19

COVID-19 outbreaks among the Miami Marlins and St. Louis Cardinals, as well as positive tests on the Cincinnati Reds, New York Mets, Oakland Athletics, and San Francisco Giants, resulted in the postponement of a total of 40 games.