The COVID-19 pandemic caused the most significant disruption to the worldwide sporting calendar since World War II. Across the world and to varying degrees, sports events were cancelled or postponed. The 2020 Summer Olympics in Tokyo were rescheduled to 2021. Only a few countries and territories—such as Hong Kong, Turkmenistan, Belarus, and Nicaragua—continued professional sporting matches as planned.

International multi-sport events

Summer Olympics

The 2020 Summer Olympics and Paralympics were scheduled to take place in Tokyo, starting 24 July and 25 August, respectively. Although the Japanese government had taken extra precautions to help minimize the outbreak's impact in the country, qualifying events were being canceled or postponed almost daily. According to Japanese public broadcaster NHK, Tokyo 2020 organizing-committee chief executive Toshiro Muto voiced concerns on 5 February that COVID-19 might "throw cold water on the momentum toward the Games."Campbell, C., Gregory, S., & Shibata, M. (2020). The Olympics-Size Risk of COVID-19. TIME Magazine, 195(7/8), 15–16.

The traditional Olympic flame lighting ceremony in Olympia, Greece, to mark the start of the 2020 Summer Olympics torch relay was held on 12 March without spectators. On 23 March, Canada, Australia, and Great Britain announced that they would withdraw from the Games unless they are postponed to 2021. On 24 March 2020, the IOC and Tokyo Organizing Committee announced that the 2020 Summer Olympics and Paralympics would be "rescheduled to a date beyond 2020 but not later than summer 2021", marking the first time in the history of the modern Olympics that an Olympiad has been postponed. The opening ceremonies of the Games were officially rescheduled to 23 July 2021, or 1,797 days from the most recent Summer Olympics in Rio de Janeiro, Brazil. The cost of postponing the Olympics to 2021 was estimated to be US$5.8 billion, which included the cost of maintaining the unused venues.

The organizing committee published various planned safety protocols for athletes, spectators, and members of the press. It was recommended that athletes be vaccinated, but they were not required to do so. On 20 March 2021, citing international travel restrictions and the need to ensure the safety of athletes, it was announced that no spectators or guests from outside of Japan would be allowed to attend the Games. This included both ticketed spectators and the supporters of athletes. While there were initially plans to allow venues to operate at half capacity (to a maximum of 10,000 spectators), it was ultimately announced that nearly the entirety of the Games would be held behind closed doors.

Furthermore, the 2024 Summer Olympics and Paralympics that were held in Paris, France on 26 July and 28 August 2024 respectively as onto the normal 4-year Olympiad schedule, were also impacted due to shorter duration ( or 1,083 days) between the last Olympics.

Winter Olympics Although the 2022 Winter Olympics hosted by Beijing, China kept their original start date of 4 February 2022 and went ahead as scheduled, the pandemic impacted qualifying in specific sports such as curling—where the World Curling Federation announced a proposal to have qualification be dependent on performance in the 2021 world championships (whose top teams will automatically qualify) and a final qualification tournament, as opposed to the previous plan of having qualification determined by both the 2020 and 2021 world championships. Qualification for the women's hockey tournament was to be determined by IIHF World Rankings after the 2020 Women's World Championship. As the tournament was cancelled, the existing rankings going into the tournament were used instead. Like in the Tokyo Summer Olympics, the games were held behind closed doors but domestic spectators were allowed to participate.

World Games The World Games in Birmingham, Alabama, were scheduled for July 2021, but because of the rescheduling of the 2020 Summer Olympics, the eleventh World Games went ahead in July 2022 instead.

Arctic Winter Games The 2020 Arctic Winter Games were cancelled.

Additionally, the 2022 Arctic Winter Games was postponed to 2023.

SEA Games/ASEAN Para Games The 2020 ASEAN Para Games in the Philippines were cancelled and 2021 SEA Games in Hanoi were postponed.

The 2021 ASEAN Para Games in Hanoi were postponed to 2022 and moved to Surakarta mid-preparation.

Summer World University Games The 2021 Summer World University Games in Chengdu, China were postponed to 2023.

Winter University The 2021 Winter Universiade in Lucerne, Switzerland, was first moved from 21–31 January to 11–21 December; on 29 November the event was cancelled.

World Masters Games The 2021 World Masters Games, originally scheduled to be held in Japan in May, were indefinitely postponed after 2022, the organisation announced on 28 October. On 12 January 2021, it was announced that the 2021 Games would be scheduled for 13–29 May 2022. It was postponed to 2026.

X Games X Games Chongli 2020 was postponed. X Games Minneapolis 2020 was cancelled.

National multi-sport governing-body competitions

Canada U Sports curtailed its men's and women's ice hockey championships on 12 March 2020. On 8 June, U Sports announced that it had cancelled all national championships for the fall semester of the 2020–21 academic year, including Canadian football (the first time the Vanier Cup was not contested since its inception), cross-country, field hockey, women's rugby, and soccer. On 15 October 2020, U Sports announced it would do the same thing for the winter 2021 portion of the 2020–21, once again cancelling all winter national championships as well. Atlantic University Sport, Canada West, and Ontario University Athletics followed suit, suspending all university athletics programs initially through to 31 December 2020, but was later extended through to 31 March 2021, as announced on 15 October 2020.

Ireland

The arrival of the COVID-19 pandemic in the Republic of Ireland had a significant impact on the conduct of sports, affecting both competitive sports leagues and tournaments and recreational sports. The Gaelic games of football, hurling, camogie, and ladies' football saw all competitions suspended from 12 March 2020. The National Hurling League, National Football League, National Camogie League and Ladies' National Football League were suspended, with competitions not intended to resume until 29 March at the earliest.

Philippines In the Philippines, NCAA Season 95 and UAAP Season 82 were both indefinitely suspended. NCAA Season 95 was terminated on 19 March after the then community quarantine in Luzon was upgraded to an "enhanced community quarantine", in effect a lockdown. UAAP Season 82 was canceled on 7 April, after the enhanced community quarantine was extended to 30 April.

On 1 May, the Cebu Schools Athletic Foundation, Inc. (CESAFI) decided to cancel their 2020 season.

United Kingdom On 16 March 2020, British Universities and Colleges Sport, the UK organisation for university sport, announced that all fixtures from 17 March to 1 April would not take place. Some individual events, like the orienteering and windsurfing championships were canceled entirely, while others were postponed indefinitely.

United States

On 6 March 2020, in the first round of the NCAA Division III men's basketball tournament, a game played at Johns Hopkins University between Yeshiva University and Worcester Polytechnic Institute became the first U.S. sporting event to be played without fans in attendance, after a student at Yeshiva University tested positive for COVID-19.

On 11 March 2020, the National Collegiate Athletic Association (NCAA) — the main U.S.A. sanctioning body for college athletics — initially announced that its winter-semester championships and tournaments, including its popular "March Madness" men's basketball tournament and the women's basketball tournament, would be conducted behind closed doors with "only essential staff and limited family attendance".

The following day, in respect of the suspension of the NBA season and other professional sports leagues, the NCAA announced that all remaining championship events for the 2019–20 academic year would be canceled entirely, resulting in the first cancellation in the 81-year history of the NCAA basketball tournament. This created a de facto mythical national championship situation. Other American multi-sports organizations—the National Association of Intercollegiate Athletics (NAIA), National Junior College Athletic Association (NJCAA), and California Community College Athletic Association (CCCAA)—also canceled their seasons. Additionally the Community College level sports governing bodies restored the season of eligibility to athletes who had already participated in the 2020 spring season.

On 12 May 2020, because the California State University system announced that in-person classes would remain suspended through the fall 2020 semester, the California Collegiate Athletic Association (CCAA)—a 12-member NCAA Division II conference consisting entirely of CSU campuses—announced that it would also suspend its fall athletics season.

The Patriot League, an NCAA Division I conference that competes in the second level of D1 Football, the Football Championship Subdivision (FCS), initially announced on 22 June that while it would hold its fall sports seasons, its teams would not fly to any competitions, and overnight travel would only be allowed on a case-by-case basis. Another FCS conference, the Ivy League, announced on 8 July that it was canceling all fall sports, and that winter sports (whose seasons normally begin during the fall academic term) would not begin play until after the end of the fall term. It left open the possibility of shifting its fall sports, including football, to the spring. The Patriot League would later cancel its fall sports season entirely on 13 July, but gave the two federally operated service academies among its membership, Army and Navy, the option to play fall sports as they saw fit. While the academies are full members of the Patriot League, their football teams play outside the conference in the top-level Football Bowl Subdivision (FBS).

The days following the Ivy League's cancellation of fall sports saw two of the major "Power Five" conferences of FBS announce that if fall sports were played, only in-conference matchups would take place. The Big Ten Conference made this announcement on 9 July, with the Pac-12 Conference doing the same the next day. Both conferences later chose to hold abbreviated conference-only football seasons, with the Big Ten starting play on the weekend of 24 October and the Pac-12 on the weekend of 7 November.

In August, the NCAA announced that the Division II and Division III Presidents Councils decided to cancel national championships in all fall sports.

In September, it was announced that 2020 Division I championships administered by NCAA in fall sports (cross country, field hockey, football soccer, women's volleyball and men's water polo) would be rescheduled to spring 2021, and conducted with a 25% reduction in championship participants. Matches played in fall or spring would count toward qualification. The Football Bowl Subdivision was not included as it is not an NCAA-administered championship.

In December, the NCAA announced that 2021 Division II championship events in winter and spring sports would also have a 25% overall reduction in participants (individual sports varied from 17 to 34% based on logistics) to mitigate costs of testing and health protocols, as well as lost income.