- January 6:
- Pro-Trump rioters storm the United States Capitol in an attempt to overturn the results of the 2020 presidential election.
- January 20:
- Joe Biden is inaugurated as the 46th president of the United States.
February:
- February 1:
- Myanmar's military seizes power in a coup d'état, detaining elected leader Aung San Suu Kyi and other top government officials.
- February 25:
- Cyclone Seroja makes landfall in Indonesia and East Timor, causing significant damage and loss of life.
March:
- March 8:
- Ethiopian Airlines Flight 302 crashes shortly after takeoff from Addis Ababa, killing all 157 people on board.
- March 11:
- The COVID-19 pandemic is declared a global pandemic by the World Health Organization (WHO).
April:
- April 15:
- Notre-Dame Cathedral in Paris is severely damaged by a fire.
May:
- May 25:
- George Floyd, an unarmed black man, is killed by a white police officer in Minneapolis, Minnesota, sparking protests against police brutality and racial inequality across the United States and the world.
June:
- June 1:
- Hurricane Douglas forms in the Pacific Ocean, becoming one of the strongest storms of the year.
- June 30:
- The United Kingdom leaves the European Union (EU), completing the Brexit process.
July:
- July 4:
- SpaceX successfully launches its first crewed mission, sending two NASA astronauts to the International Space Station (ISS).
- July 29:
- Hurricane Hanna makes landfall in Texas, causing damage along the Gulf Coast.
August:
- August 4:
- A powerful explosion occurs in Beirut, Lebanon, destroying much of the city's port and causing widespread damage and casualties.
- August 17:
- Three people are killed and several injured in a shooting in Kenosha, Wisconsin, sparking protests and civil unrest.
September:
- September 18:
- Ruth Bader Ginsburg, a Supreme Court justice and liberal icon, dies at the age of 87.
- September 27:
- Armenia and Azerbaijan clash in a renewed conflict over the disputed Nagorno-Karabakh region.
October:
- October 2:
- President Donald Trump and Democratic challenger Joe Biden participate in the first presidential debate of the 2020 election campaign.
- October 10:
- Super Typhoon Goni makes landfall in the Philippines, causing widespread damage and flooding.
November:
- November 3:
- The 2020 United States presidential election takes place, with Joe Biden defeating incumbent Donald Trump.
- November 13:
- Ethiopia declares a state of emergency as fighting intensifies in the Tigray region.
December:
- December 11:
- The United Kingdom approves the Pfizer-BioNTech COVID-19 vaccine, becoming the first country in the world to do so.
- December 21:
- The Great Conjunction occurs, a rare astronomical event in which Jupiter and Saturn appear exceptionally close to each other in the night sky.