2011 (MMXI) was a common year starting on Saturday of the Gregorian calendar, the 2011th year of the Common Era (CE) and Anno Domini (AD) designations, the 11th year of the 3rd millennium, the 11th year of the 21st century, and the 2nd year of the 2010s decade.
2011 was designated as:
- International Year of Forests
- International Year of Chemistry
- International Year for People of African Descent
- January 1
- January 4 – Tunisian street vendor Mohamed Bouazizi dies after setting himself on fire a month earlier, sparking anti-government protests in Tunisia and later other Arab nations. These protests become known collectively as the Arab Spring.
- January 9 – Iran Air Flight 277 crashes near Orumiyeh in the northeast of the country, killing 77 people.
- January 9–15 – Southern Sudan holds a referendum on independence. The Sudanese electorate votes in favour of independence, paving the way for the creation of the new state in July.
- January 14 – The Tunisian government falls after a month of increasingly violent protests; President Zine El Abidine Ben Ali flees to Saudi Arabia after 23 years in power.
- January 24 – 37 people are killed and more than 180 others wounded in a bombing at Domodedovo International Airport in Moscow, Russia.
- February 11 – Egyptian President Hosni Mubarak resigns after widespread protests calling for his departure, leaving control of Egypt in the hands of the military until a general election can be held.
- February 15 – The First Libyan Civil War starts.
- February 22 – March 14 – Uncertainty over Libyan oil output causes crude oil prices to rise 20% over a two-week period following the Arab Spring, causing the 2011 energy crisis.
- February 22 – A 6.3 magnitude earthquake strikes Christchurch, New Zealand. Over 180 people were killed, many within the CTV Building, including a large number of foreign citizens. A large number of foreign search and rescue workers responded to the event.
- March 6 – Civil uprising phase of the Syrian Civil War is triggered when 15 youths in Daraa are arrested for scrawling graffiti on their school wall denouncing the regime of President Bashar al-Assad.
- March 11 – A 9.0-magnitude earthquake and subsequent tsunami hit the east of Japan, killing 15,840 and leaving another 3,926 missing. Tsunami warnings are issued in 50 countries and territories. Emergencies are declared at four nuclear power plants affected by the quake.
- March 15
- Hamad bin Isa Al Khalifa, King of Bahrain, declares a three-month state of emergency as troops from the Gulf Co-operation Council are sent to quell the civil unrest.
- Protests breakout across Syria demanding democratic reforms, resignation of President Bashar al-Assad, and release of those imprisoned for the March 6 Daraa protest. The government responds by killing hundreds of protesters and laying siege to various cities, beginning the Syrian Civil War.
- March 17 – The United Nations Security Council votes 10–0 to create a no-fly zone over Libya in response to allegations of government aggression against civilians.
- March 19 – In light of continuing attacks on Libyan rebels by forces in support of leader Muammar Gaddafi, military intervention authorized under UNSCR 1973 begins as French fighter jets make reconnaissance flights over Libya.
- April 2 – India wins the 2011 Cricket World Cup.
- April 11 – Former Ivorian President Laurent Gbagbo is arrested in his home in Abidjan by supporters of elected President Alassane Ouattara, with support from French forces; this effectively ends the 2010–11 Ivorian crisis and civil war.
- April 15 – The Mexican town of Cherán is taken over by vigilantes in response to abuses from the local drug cartel. The new government is strongly focused on crime reduction and preserving the local environment.
- April 25–28 – The 2011 Super Outbreak forms in the Southern, Midwest and Eastern United States with a tornado count of 362; killing 324 and injuring over 2,200.
- April 29 – An estimated two billion people watch the wedding of Prince William, Duke of Cambridge and Catherine Middleton at Westminster Abbey in London.
- May 1 – U.S. President Barack Obama announces that Osama bin Laden, the founder and leader of the militant group Al-Qaeda, was killed on May 2, 2011 (PKT, UTC+05) during an American military operation in Pakistan.
- May 10–14 – The Eurovision Song Contest 2011 takes place in Düsseldorf, Germany, and is won by Azeri entrants Ell & Nikki with the song "Running Scared".
- May 16 – The European Union agrees to a €78 billion rescue deal for Portugal. The bailout loan will be equally split between the European Financial Stabilisation Mechanism, the European Financial Stability Facility, and the International Monetary Fund.
- May 21 – Grímsvötn, Iceland's most active volcano, erupts and causes disruption to air travel in Northwestern Europe.
- May 22 – The 2011 Joplin tornado, an EF5 tornado, strikes Joplin, Missouri, killing 158 and injuring 1,150.
- May 26 – Former Bosnian Serb Army commander Ratko Mladić, wanted for genocide, war crimes and crimes against humanity, is arrested in Serbia.
- June 4 – Chile's Puyehue volcano erupts, causing air traffic cancellations across South America, New Zealand and Australia, and forcing over 3,000 people to evacuate.
- June 26 – July 17 – The 2011 FIFA Women's World Cup takes place in Germany and is won by Japan.
- June 28 – The Food and Agriculture Organization announces the eradication of the cattle plague rinderpest from the world.
- July 9 – South Sudan secedes from Sudan, per the result of the independence referendum held in January.
- July 12 – The planet Neptune completes its first orbit since it was discovered in 1846.
- July 14 – South Sudan joins the United Nations as the 193rd member.
- July 20
- Goran Hadžić is detained in Serbia, becoming the last of 161 people indicted by the International Criminal Tribunal for the former Yugoslavia.
- The United Nations declares a famine in southern Somalia, the first in over 30 years.
- July 21 – Space Shuttle Atlantis lands successfully at Kennedy Space Center after completing STS-135, concluding NASA's Space Shuttle program.
- July 22 – In Norway, Anders Behring Breivik kills 8 people in a bomb blast which targeted government buildings in central Oslo, then kills 69 at a massacre at a Workers' Youth League camp on the island of Utøya.
- July 31 – In Thailand over 12.8 million people are affected by severe flooding. The World Bank estimates damages at 1,440 billion baht (US$45 billion). Some areas are still six feet under water, and many factory areas remain closed at the end of the year. 815 people are killed, with 58 of the country's 77 provinces affected.
- August – Stock exchanges worldwide suffer heavy losses due to the fears of contagion of the European sovereign debt crisis and the credit rating downgraded as a result of the debt-ceiling crisis of the United States.
- August 5
- August 20–28 – Libyan rebels take control of the capital Tripoli, effectively overthrowing the government of Muammar Gaddafi.
- September 5 – India and Bangladesh sign a pact to end their 40-year border demarcation dispute.
- September 10 – The MV Spice Islander I, carrying at least 800 people, sinks off the coast of Zanzibar, killing 240 people.
- September 12 – Approximately 100 people die after a petrol pipeline explodes in Nairobi.
- September 17 – Occupy Wall Street protests begin in the United States. This develops into the Occupy movement which spreads to 82 countries by October.
- September 19 – With 434 dead, the United Nations launches a $357 million appeal for victims of the 2011 Sindh floods in Pakistan.
- October 4 – The death toll from the flooding of Cambodia's Mekong river and attendant flash floods reaches 207.
- October 18 – Gilad Shalit prisoner exchange: Israel and the Palestinian militant organization Hamas begin a major prisoner exchange, in which the captured Israeli Army soldier Gilad Shalit is released by Hamas in exchange for 1,027 Palestinian and Israeli-Arab prisoners held in Israel, including 280 prisoners serving life sentences for planning and perpetrating terror attacks.
- October 20
- October 23 – A magnitude 7.2 Mw earthquake jolts eastern Turkey near the city of Van, killing over 600 people and damaging about 2,200 buildings.
- October 27 – After an emergency meeting in Brussels, the European Union announces an agreement to tackle the European sovereign debt crisis which includes a writedown of 50% of Greek bonds, a recapitalisation of European banks and an increase of the bailout fund of the European Financial Stability Facility totaling to €1 trillion.
- October 31
- November 26 –The Mars Science Laboratory rover Curiosity, the most elaborate Martian exploration vehicle to date, is launched from the Kennedy Space Center. It lands on Mars on August 6, 2012.
- November 30 – The United Kingdom severs diplomatic relations with Iran and expels diplomats, less than 24 hours after protesters attacked the British embassy in Tehran.
- December 15 – The United States formally declares an end to the Iraq War. While this ends the insurgency, it begins another.
- December 16 – Tropical Storm Washi causes 1,268 flash flood fatalities in the Philippines, with 85 people officially listed as missing.
- December 29 – Samoa and Tokelau move from east to west of the International Date Line, thereby skipping December 30, in order to align their time zones better with their main trading partners.
- January 2
- January 4
- January 10
- January 11 – David Nelson, American actor, director and producer (b. 1936)
- January 15
- January 18 – Sargent Shriver, American diplomat, politician, and activist (b. 1915)
- January 21 – Dennis Oppenheim, American artist (b. 1938)
- January 27 – Charlie Callas, American comedian and actor (b. 1924)
- January 29 – Milton Babbitt, American composer (b. 1916)
- January 30 – John Barry, English composer (b. 1933)
- February 3 – Maria Schneider, French actress (b. 1952)
- February 4 – Martial Célestin, 1st Prime Minister of Haiti (b. 1913)
- February 5 – Brian Jacques, British author (b. 1939)
- February 6
- February 8 – Cesare Rubini, Italian basketball player and coach (b. 1923)
- February 12
- February 14 – George Shearing, British-American jazz pianist (b. 1919)
- February 16 – Len Lesser, American actor (b. 1922)
- February 23 – Shri Mataji Nirmala Srivastava, Indian founder of Sahaja Yoga (b. 1923)
- February 27
- February 28
- March 2 – Allan Louisy, 2nd Prime Minister of Saint Lucia (b. 1916)
- March 4
- March 5 – Alberto Granado, Cuban writer and scientist (b. 1922)
- March 6 – Ján Popluhár, Slovak footballer (b. 1935)
- March 8 – Mike Starr, American musician (b. 1966)
- March 15 – Nate Dogg, American rapper (b. 1969)
- March 17
- March 18 – Warren Christopher, American diplomat (b. 1925)
- March 21
- March 23 – Elizabeth Taylor, British-American actress (b. 1932)
- March 26
- March 27 – Farley Granger, American actor (b. 1925)
- March 29 – José Alencar, Brazilian politician, 23rd Vice President of Brazil (b. 1931)
- April 4
- April 5
- April 9 – Sidney Lumet, American film director (b. 1924)
- April 14 – William Lipscomb, American chemist (b. 1919)
- April 17 – Michael Sarrazin, Canadian actor (b. 1940)
- April 19
- April 21 – Tim Hetherington, British photojournalist (b. 1970)
- April 24 – Sathya Sai Baba, Indian spiritual leader (b. 1926)
- April 25
- April 30 – Ernesto Sabato, Argentine writer (b. 1911)
- May 1 – Henry Cooper, British heavyweight boxer (b. 1934)
- May 2 – Osama bin Laden, Saudi-born leader of Al-Qaeda (b. 1957)
- May 3 – Jackie Cooper, American actor (b. 1922)
- May 4 – Sada Thompson, American actress (b. 1927)
- May 5
- May 7
- May 8 – Lionel Rose, Australian boxer (b. 1948)
- May 9 – Lidia Gueiler Tejada, 67th President of Bolivia (b. 1921)
- May 15 – Samuel Wanjiru, Kenyan athlete (b. 1986)
- May 17 – Harmon Killebrew, American baseball player (b. 1936)
- May 18 – Guy Razanamasy, 2-Time Prime Minister of Madagascar (b. 1928)
- May 19 – Garret FitzGerald, 7th Taoiseach of Ireland (b. 1926)
- May 20 – Randy Savage, American professional wrestler (b. 1952)
- May 23
- May 27
- May 29
- May 30 – Rosalyn Sussman Yalow, American physicist (b. 1921)
- May 31 – Pauline Betz, American tennis player (b. 1919)
- June 3
- June 4 – Lawrence Eagleburger, American diplomat (b. 1930)
- June 5 – Ludo Martens, Belgian writer and political activist (b. 1946)
- June 7 – Jorge Semprún, Spanish writer and politician (b. 1923)
- June 9
- June 10
- June 18
- June 20 – Ryan Dunn, American television personality (b. 1977)
- June 23 – Peter Falk, American actor (b. 1927)
- June 29 – Bob Brunning, British musician (b. 1943)
- July 2 – Itamar Franco, 37th President of Brazil (b. 1930)
- July 4 – Archduke Otto of Austria, (b. 1912)
- July 5 – Cy Twombly, American painter (b. 1928)
- July 8
- July 9 – Facundo Cabral, Argentine singer (b. 1937)
- July 10 – Roland Petit, French choreographer and dancer (b. 1924)
- July 12 – Tom Gehrels, American astronomer (b. 1925)
- July 15 – Friedrich Wilhelm Schnitzler, German landowner, politician, and businessman (b. 1928)
- July 17 – Juan María Bordaberry, 36th President of Uruguay (b. 1928)
- July 20 – Lucian Freud, German-born British painter (b. 1922)
- July 23
- July 24 – G. D. Spradlin, American actor (b. 1920)
- July 25 – Mihalis Kakogiannis, Cypriot filmmaker (b. 1922)
- July 26 – Joe Arroyo, Colombian salsa and tropical music singer (b. 1955)
- July 28 – Abdul Fatah Younis, Libyan army commander (b. 1944)
- July 30 – Mario Echandi Jiménez, 47th President of Costa Rica (b. 1915)
- August 2 – Baruj Benacerraf, Venezuelan-born American Nobel immunologist (b. 1920)
- August 3 – Bubba Smith, American football player and actor (b. 1945)
- August 4 – Naoki Matsuda, Japanese footballer (b. 1977)
- August 5
- August 6 – John Wood, English actor (b. 1930)
- August 7
- August 14 – Shammi Kapoor, Indian film actor and director (b. 1931)
- August 16 – Andrej Bajuk, 3rd Prime Minister of the Republic of Slovenia (b. 1943)
- August 17 – Pierre Quinon, French pole vaulter (b. 1962)
- August 19 – Raúl Ruiz, Chilean film director (b. 1941)
- August 22
- August 31 – Valery Rozhdestvensky, Soviet-Russian cosmonaut (b. 1939)
- September 8 – Võ Chí Công, 5th President of Vietnam (b. 1912)
- September 10 – Cliff Robertson, American actor (b. 1923)
- September 11
- September 12 – Alexander Galimov, Russian hockey player (b. 1985)
- September 13 – Richard Hamilton, British painter and collage artist (b. 1922)
- September 14 – Rudolf Mössbauer, German Nobel physicist (b. 1929)
- September 15 – Frances Bay, Canadian-American character actress (b. 1919)
- September 19 – George Cadle Price, 1st Prime Minister of Belize (b. 1919)
- September 20 – Burhanuddin Rabbani, President of Afghanistan from 1992 to 1996 (b. 1940)
- September 21 – Troy Davis, American murderer (b. 1968)
- September 22
- September 25 – Wangari Maathai, Kenyan veterinary anatomist and Nobel Peace Prize laureate (b. 1940)
- September 27 – Imre Makovecz, Hungarian architect (b. 1935)
- September 29
- September 30
- October 1 – Sven Tumba, Swedish hockey player (b. 1931)
- October 4 – Doris Belack, American actress (b. 1926)
- October 5
- October 6 – Diane Cilento, Australian actress and author (b. 1933)
- October 7 – Ramiz Alia, 1st President of Albania (b. 1925)
- October 8 – Mikey Welsh, American musician and artist (b. 1971)
- October 10 – Jagjit Singh, Indian singer, composer and musician (b. 1941)
- October 11 – Frank Kameny, American gay rights activist (b. 1925)
- October 12 – Dennis Ritchie, American computer scientist (b. 1941)
- October 16 – Dan Wheldon, English racing car driver (b. 1978)
- October 18 – Norman Corwin, American radio writer, director and producer (b. 1910)
- October 20
- October 22 – Sultan, Crown Prince of Saudi Arabia, (b. 1930)
- October 23
- October 24 – John McCarthy, American computer scientist (b. 1927)
- October 26 – Jona Senilagakali, Prime Minister of Fiji (b. 1929)
- October 29 – Jimmy Savile, English DJ, television presenter, media personality, and charity fundraiser (b. 1926)
- October 31
- November 4
- November 7 – Joe Frazier, American boxer (b. 1944)
- November 8
- November 9 – Har Gobind Khorana, Indian-born American Nobel biochemist (b. 1922)
- November 11 – Francisco Blake Mora, Mexican politician (b. 1966)
- November 19 – John Neville, English actor (b. 1925)
- November 21 – Anne McCaffrey, American-born Irish writer (b. 1926)
- November 22
- November 25 – Vasily Alekseyev, Soviet-Russian weightlifter (b. 1942)
- November 27
- November 28
- November 29 – Patrice O'Neal, American comedian and radio personality (b. 1969)
- December 1 – Christa Wolf, German writer (b. 1929)
- December 3
- December 4
- December 5 – Violetta Villas, Polish singer (b. 1938)
- December 7 – Harry Morgan, American actor (b. 1915)
- December 11 – John Patrick Foley, American cardinal (b. 1935)
- December 13
- December 14
- December 15 – Christopher Hitchens, British-American writer (b. 1949)
- December 16
- December 17
- December 18 – Václav Havel, Czech playwright, 10th President of Czechoslovakia and 1st President of the Czech Republic (b. 1936)
- December 21 – Yevhen Rudakov, Ukrainian footballer (b. 1942)
- December 22 – William Duell, American actor and singer (b. 1923)
- December 24 – Johannes Heesters, Dutch actor and singer (b. 1903)
- December 26
- December 27 – Helen Frankenthaler, American abstract expressionist painter (b. 1928)
- Chemistry – Dan Shechtman
- Economics – Christopher A. Sims and Thomas J. Sargent
- Literature – Tomas Tranströmer
- Peace – Ellen Johnson Sirleaf, Leymah Gbowee and Tawakkol Karman
- Physics – Saul Perlmutter, Adam G. Riess, and Brian P. Schmidt
- Physiology or Medicine – Bruce A. Beutler, Jules A. Hoffmann, and Ralph M. Steinman
New English words