2009

+ Austria, Japan, Mexico, Turkey and Uganda assume their seats on the United Nations Security Council.
	+ Asunción, the capital of Paraguay, becomes the American Capital of Culture and Vilnius and Linz become the European Capitals of Culture.
	+ Slovakia adopts the euro as its national currency, replacing the Slovak koruna.
	+ Sixty-six nightclub-goers die in the Santika Club fire in Bangkok, Thailand.
* January 3 – The first ("Genesis") block of the blockchain of the cryptocurrency and decentralized payment system Bitcoin is established by the creator of the system, known as Satoshi Nakamoto.
* January 15 – US Airways Flight 1549 ditches in the Hudson River in an accident that becomes known as the "Miracle on the Hudson" as all 155 people on board are rescued.
* January 18 – Gaza War: Hamas announces they will accept Israel Defense Forces offer of a ceasefire, ending the conflict.
* January 20
	+ A protest movement in Iceland culminates as the 2009 Icelandic financial crisis protests start.
	+ Barack Obama is sworn in as the 44th President of the United States, becoming the first African-American to hold the office.
* January 21 – Israel withdraws from the Gaza Strip, officially ending its three-week war with Hamas. However, intermittent air strikes by both sides continue in the weeks to follow.
* January 26
	+ The first trial at the International Criminal Court is held. Former Union of Congolese Patriots leader Thomas Lubanga is accused of training child soldiers to kill, pillage, and rape.
	+ The Icelandic government and banking system collapse. Prime Minister Geir Haarde immediately resigns.
	+ An annular solar eclipse took place in Indian Ocean, and was the 50th solar eclipse of Saros cycle 131.

### February

* February 1
	+ Patriarch Kirill of Moscow is enthroned as the Patriarch of the Russian Orthodox Church following the death of his predecessor, Alexy II in 2008.
	+ Jóhanna Sigurðardóttir is appointed as the new Prime Minister of Iceland, becoming the world's first openly lesbian head of government.
* February 25 – Soldiers of Bangladeshi border security force Bangladesh Rifles (BDR) mutiny and take the commanding army officers and their families hostages at the force's headquarters in Pilkhana, Dhaka. 57 army officers are killed along with 17 civilians by the mutineers.
* February 26 – Former Serbian president Milan Milutinovic is acquitted by the International Criminal Tribunal for the former Yugoslavia regarding war crimes during the Kosovo War.

### March

* March 2 – The President of Guinea-Bissau, João Bernardo Vieira, is assassinated during an armed attack on his residence in Bissau.
* March 4 – The International Criminal Court issues an arrest warrant for Sudanese President Omar al-Bashir for war crimes and crimes against humanity in Darfur. al-Bashir is the first sitting head of state to be indicted by the ICC since its establishment in 2002.
* March 7 – NASA's Kepler Mission, a space photometer that will search for extrasolar planets in the Milky Way galaxy, is launched from Cape Canaveral Air Force Station, Florida, USA.
* March 17 – The President of Madagascar, Marc Ravalomanana, is overthrown in a coup d'état, following a month of unrest in Antananarivo.

### April

* April 1 – Albania and Croatia are admitted to NATO, becoming the newest members of the organization.
* April 4 – Three Pittsburgh Police Officers are shot and killed responding to a domestic dispute in the Stanton Heights (Pittsburgh) section of the city.
* April 5 – North Korea launches a rocket from its Tonghae Satellite Launching Ground, which it says is carrying the Kwangmyongsong-2 satellite, prompting an emergency meeting of the United Nations Security Council.
* April 6 – A 6.3 magnitude earthquake strikes near L'Aquila, Italy, killing 308 and injuring more than 1,500.
* April 21 – UNESCO launches The World Digital Library.

### May

* May 18 – Following more than a quarter-century of fighting, the Sri Lankan Civil War ends with the total military defeat of the Liberation Tigers of Tamil Eelam.
* May 25 – North Korea announces that it has conducted a second successful nuclear test in North Hamgyong Province. The United Nations Security Council condemns the reported test.

### June

* June 1 – Air France Flight 447, en route from Rio de Janeiro, Brazil, to Paris, crashes into the Atlantic Ocean, killing all 228 on board.
* June 11 – The outbreak of the H1N1 influenza strain, commonly referred to as "swine flu", is deemed a global pandemic.
* June 13 – Mass protests erupt across Iran following a disputed presidential election in which Mahmoud Ahmadinejad was reelected president, the largest demonstrations in the country since the Iranian Revolution.
* June 18 – NASA launches the Lunar Reconnaissance Orbiter / LCROSS probes to the Moon, the first American lunar mission since Lunar Prospector in 1998.
* June 21 – Greenland gains self-rule.
* June 28 – The Military of Honduras ousts Honduran President Manuel Zelaya in a *coup d'état*, which is condemned worldwide.
* June 30 – Yemenia Flight 626 crashes off the coast of Moroni, Comoros, killing all but one of the 153 passengers and crew.

### July

* July 15 – Caspian Airlines Flight 7908 crashes near Qazvin, Iran, killing all 168 on board.
* July 16 – Iceland's national parliament, the Althingi, votes to pursue joining the EU.
* July 22 – The longest total solar eclipse of the 21st century, lasting up to 6 minutes and 38.8 seconds, occurs over parts of Asia and the Pacific Ocean.
* July 26 – The Islamic extremist group Boko Haram initiates an uprising in Bauchi State, Nigeria and quickly spreads throughout the northern part of the country.

### August

* August 3 – Bolivia becomes the first South American country to declare the right of indigenous people to govern themselves.
* August 7 – Typhoon Morakot hits Taiwan, killing 673 and stranding more than 1,000 via the worst flooding on the island in half a century.
* August 14 – The United Kingdom imposes direct rule on the Turks and Caicos Islands after an inquiry that found evidence of government corruption.

### September

* September 28 – At least 157 demonstrators are massacred by the Guinean military at the Stade du 28 Septembre during a protest against the government that came to power in a coup d'état the previous year.
* September 30 – A 7.6 earthquake strikes Sumatra, Indonesia, with a maximum Mercalli intensity of VIII (*Severe*), leaving at least 1,115 people dead.

### October

* October 1 – Paleontologists announce the discovery of an *Ardipithecus ramidus* fossil skeleton, deeming it the oldest remains of a human ancestor yet found.
* October 2
	+ Ireland holds a second referendum on the EU's Lisbon Treaty. The amendment is approved by the Irish electorate, having been rejected in the Lisbon I referendum held last year.
	+ The International Olympic Committee awards Rio de Janeiro the right to host the 2016 Summer Olympics.
* October 25 – Two suicide attacks in Baghdad, Iraq, kill 155 people and injure at least 721 people.

### November

* November 3
	+ The Czech Republic becomes the final member-state of the European Union to sign the Treaty of Lisbon, thereby permitting that document's initiation into European law.
	+ The Prime Minister of Belgium, Herman Van Rompuy, is designated the first permanent President of the European Council, a position he takes up on December 1, 2009.
* November 13 – Having analyzed the data from the LCROSS lunar impact, NASA announces that it has found a "significant" quantity of water in the Moon's Cabeus crater.
* November 23 – In the Philippines, at least 58 people are abducted and killed in the province of Maguindanao, in what the Committee to Protect Journalists called the single deadliest attack on journalists in history.

### December

* December 1 – The Treaty of Lisbon comes into force.
* December 7–18 – The UNFCCC's 2009 United Nations Climate Change Conference is held in Copenhagen, Denmark.
* December 8 – A series of attacks in Baghdad, Iraq kill at least 127 people and injure at least 448 more.
* December 10 – James Cameron's *Avatar*, which has since been the highest-grossing film of all time, premieres in the United Kingdom.
* December 16 – Astronomers discover GJ 1214 b, the first-known exoplanet on which water could exist.