January 3 - A U.S. drone strike at Baghdad International Airport kills Iranian general Qasem Soleimani and Iraqi paramilitary leader Abu Mahdi al-Muhandis.
January 8 - Ukraine International Airlines Flight 752 is mistakenly shot down by Iran's armed forces shortly after takeoff from Tehran Imam Khomeini Airport, killing all 176 people on board.
January 9 - A rare, circumbinary planet called TOI 1338-b is discovered.
January 10 - The Sultan of Oman, Qaboos bin Said, dies aged 79. Haitham bin Tariq is sworn in as his successor.
January 29 - U.S. president Donald Trump signs the United States–Mexico–Canada Agreement, a North American trade agreement set to replace NAFTA.
January 31 - The United Kingdom and Gibraltar formally withdraw from the European Union, beginning an 11-month transition period.
February 11 – The World Health Organization (WHO) names the disease COVID-19.
February 24 – The Pakatan Harapan coalition government of Malaysia collapses and is replaced by the Perikatan Nasional coalition.
February 29 – A conditional peace agreement is signed between the U.S. and the Taliban in Doha, Qatar, leading the U.S. to begin gradually withdrawing troops from Afghanistan on March 10.
March 5 - The International Criminal Court authorizes the Afghanistan War Crimes inquiry to proceed, reportedly allowing for the first time for U.S. citizens to be investigated.
March 11 - The World Health Organization declares the COVID-19 outbreak a pandemic.
March 20 - The Bhadla Solar Park is commissioned and becomes the world's largest solar park.
March 24 - The International Olympic Committee and Japan suspend the 2020 Summer Olympics until 2021.
March 27 - North Macedonia becomes the 30th country to join NATO.
April 6 – The United States designates the Russian Imperial Movement as a terrorist organization and imposes sanctions on its leaders; it is the first white supremacist group the U.S. has designated as a terrorist organization.
April 8 – The Saudi-led coalition declares a unilateral ceasefire in its operations against Houthi forces in Yemen in accordance with United Nations-led efforts.
April 15 – The 2020 Tour de France is delayed until August 2020 due to the COVID-19 pandemic.
April 26 – King Salman issues a royal decree, declaring that people will no longer be executed in Saudi Arabia for crimes they were convicted of when they were minors.
April 30 – NASA officially selects SpaceX, Blue Origin, and Dynetics to build its next-generation lunar lander to carry American astronauts to the Moon by 2024.
May 4 – A team of British and Kenyan scientists announce the discovery of Microsporidia MB, a parasitic microbe in the Microsporidia fungi group that blocks mosquitos from carrying malaria, potentially paving the way for the control of malaria.
May 10 – The Iranian Navy frigate Jamaran accidentally strikes the Iranian support vessel Konarak with a missile, killing nineteen sailors.
May 22 – Flight PK8303, a Pakistan International Airlines passenger aircraft, crashes in a residential area near Karachi, in Pakistan, killing 97 of the 99 total people on board and injuring dozens on the ground.
May 26 – Costa Rica becomes the first Central American country to legalise same-sex marriage.
June 3 – SpaceX successfully launches and deploys 60 Starlink satellites into a low Earth orbit from Cape Canaveral Air Force Station, bringing the total number of Starlink satellites in orbit to 482.
June 3 – Russian President Vladimir Putin declares a state of emergency after 20,000 tons of oil leaked into the Ambarnaya River near the Siberian city of Norilsk within the Arctic Circle on May 26, 2020.
June 4 – Hong Kong legislative council passed the controversial National Anthem Ordinance.
June 16 – North Korea demolishes the Inter-Korean Liaison Office in Kaesong, established in 2018 to improve relations.
June 27 – Micheál Martin succeeds Leo Varadkar as Taoiseach of Ireland in a historic three-party coalition government.
June 30 – China passes the controversial Hong Kong national security law, allowing China to crack down on opposition to Beijing at home or abroad.
July 10 – Turkey's President Recep Tayyip Erdoğan orders the Hagia Sophia in Istanbul to be reverted to a mosque following a supreme court annulment of a 1934 presidential decree that made it into a museum.
July 30 – NASA successfully launches its Mars 2020 rover mission to search for signs of ancient life and collect samples for return to Earth. The mission includes technology demonstrations to prepare for future human missions.
August 1 – The Barakah nuclear power plant in the UAE becomes operational following delays since 2017. It is the first commercial nuclear power station in the Arab world.
August 13 – Israel and the UAE agree to normalise relations, marking the third Israel–Arab peace deal.
August 23 – Bayern Munich wins the 2019–20 UEFA Champions League by beating Paris Saint-Germain in the final.
August 25 – Africa is declared free of wild polio, the second virus to be eradicated from the continent since smallpox 40 years previously.
August 28 – Japanese Prime Minister Shinzo Abe, the longest-serving prime minister in the history of Japan, announces his resignation from office, citing ill health.
September 3 – Sudanese Prime Minister Abdalla Hamdok and Abdelaziz al-Hilu, the leader of the Sudan People's Liberation Movement-North (SPLM–N), sign an agreement to transition the country into a secular state.
September 4 – Bahrain and Israel agree to normalise relations, marking the fourth Israel–Arab peace deal.
September 16 – Yoshihide Suga becomes the new Prime Minister of Japan, replacing Shinzo Abe.
September 29 – The Emir of Kuwait Sheikh Sabah al-Sabah dies at the age of 91. Crown Prince Nawaf Al-Ahmad Al-Jaber Al-Sabah is named his successor.
October 1 – The EU began legal proceedings against the UK after it ignored their deadline to drop controversial sections from its internal market Bill.
October 10 – Armenia and Azerbaijan agree on a ceasefire in the ongoing Nagorno-Karabakh conflict.
October 17 – 2020 New Zealand general election: Jacinda Ardern's Labour Party wins a landslide second term in office, defeating the National Party.
October 22 – The Geneva Consensus Declaration on Promoting Women's Health and Strengthening the Family is signed by government representatives from 34 countries.
November 1 – Former Prime Minister and Minister of Education Maia Sandu is elected as the 6th President of Moldova, becoming the first woman to ever hold the post.
November 3-7 – Joe Biden is elected as the 46th President of the United States, after remaining vote counts (November 7) come in from key states.
November 4 – The United States formally exits the Paris Agreement on climate change.
November 9 – Armenia and Azerbaijan sign a Russia-brokered ceasefire agreement.
November 15 – The Regional Comprehensive Economic Partnership (RCEP) is signed by 15 Asia-Pacific countries to form the world's largest free-trade bloc, covering a third of the world's population.
November 27 – Iran's top nuclear scientist, Mohsen Fakhrizadeh, is assassinated near Tehran.
December 10 – Israel and Morocco normalise diplomatic relations.
December 14 – The United States removes Sudan from its list of state sponsors of terrorism.
December 14 – The United States places sanctions on Turkey in retaliation for their purchase of a S-400 missile system from Russia, making the first time they have sanctioned a NATO ally.
December 15 – The International Criminal Court accuses the Philippines of crimes against humanity in its war on drugs.
December 24 – The United Kingdom and the European Union agree to a comprehensive free trade agreement prior to the end of the transition period.
December 31 – The transition period following the United Kingdom's exit from the European Union on 31 January 2020 expires.