2011 (MMXI) was a common year starting on Saturday (dominical letter B) 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
It was marked by a wave of revolutions in the Arab World known as the Arab Spring, including the beginnings of several unresolved protest movements and armed conflicts.
- January 1 – Estonia officially adopts the Euro currency and becomes the 17th Eurozone country.
- 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 – 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 – Arab Spring: 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 – Arab Spring: 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 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.
- 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
- March 17 – Arab Spring and the Libyan Civil War: 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 – Arab Spring and the Libyan civil war: 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 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 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 during an American military operation in Pakistan.
- 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, erupted and caused disruption to air travel in Northwestern Europe.
- 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, Australia and forcing over 3,000 people to evacuate.
- June 5 – Arab Spring: Yemeni President Ali Abdullah Saleh travels to Saudi Arabia for treatment of an injury sustained during an attack on the presidential palace. Protesters celebrate his transfer of power to his Vice-President Abd al-Rab Mansur al-Hadi.
- June 12 – Arab Spring: Thousands of Syrians flee to Turkey as Syrian troops lay siege to Jisr ash-Shugur.
- June 28 – Food and Agriculture Organization announces the eradication of the cattle plague rinderpest from the world.
- July 7 – The world's first artificial organ transplant is achieved, using an artificial windpipe coated with stem cells.
- 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
- July 21 – Space Shuttle Atlantis lands successfully at Kennedy Space Center after completing STS-135, concluding NASA's Space Shuttle program.
- July 22 – Anders Behring Breivik kills 77 people in twin terrorist attacks in Norway, after a bombing in the Regjeringskvartalet government center in Oslo and a shooting at a political youth camp on the island of Utøya.
- July 28 – Asiana Airlines Flight 991, a Boeing 747-400F, from Incheon International Airport to Shanghai Pudong International Airport crashed near Jeju Island because of a cargo fire emergency when the plane crossed the B576 air route. The plane tried to divert to Jeju International Airport but it crashed off Jeju Island.(Crew:2/Death:2/Survivor:0)
- 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 remained closed at the end of the year. 815 people are killed, with 58 of the country's 77 provinces affected.
- Arab Spring: Because of the uncertaintities associated with a clamp-down of the free press, there are believed to be at least 121 people killed in a Syrian Army tank raid on the town of Hama and over 150 people are reportedly killed across the country. The total dead throughout Syria may never be known, but an estimate as of September 24 is 3,000.
- 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 – Arab Spring and the Libyan civil war: In the Battle of Tripoli, Libyan rebels take control of the nation's capital, 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 – Israel and the Palestinian militant organization Hamas begin a major prisoner swap, 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
- Arab Spring and the Libyan civil war: Libyan leader Muammar Gaddafi is killed in Sirte, with National Transitional Council forces taking control of the city, and ending the war.
- Basque separatist militant organisation ETA declares an end to its 43-year campaign of political violence, which has killed over 800 people since 1968.
- 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.
- 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 15
- January 18 – Sargent Shriver, American politician and diplomat (b. 1915)
- January 21 – Dennis Oppenheim, American artist (b. 1938)
- January 24 – Bernd Eichinger, German film producer and director (b. 1949)
- 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 5 – Brian Jacques, British author (b. 1939)
- February 6
- February 8 – Cesare Rubini, Italian basketball player and coach (b. 1923)
- February 14 – George Shearing, British-American jazz pianist (b. 1919)
- February 27 – Necmettin Erbakan, 25th Prime Minister of Turkey (b. 1926)
- February 28 – Jane Russell, American actress (b. 1921)
- March 4
- March 5 – Alberto Granado, Cuban writer and scientist (b. 1922)
- March 6 – Ján Popluhár, Slovak footballer (b. 1935)
- March 15 – Nate Dogg, American rapper (b. 1969)
- March 17 – Michael Gough, British actor (b. 1916)
- March 18 – Warren Christopher, American diplomat (b. 1925)
- March 21 – Nikolai Andrianov, Soviet-Russian gymnast (b. 1952)
- 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 (b. 1931)
- April 5
- April 9 – Sidney Lumet, American film director (b. 1924)
- April 14 – William Lipscomb, American chemist (b. 1919)
- April 19 – Grete Waitz, Norwegian athlete (b. 1953)
- April 24 – Sathya Sai Baba, Indian spiritual leader (b. 1926)
- April 30 – Ernesto Sabato, Argentine writer (b. 1911)
- May 2 – Osama bin Laden, Saudi-born leader of Al-Qaeda (b. 1957)
- May 3 – Jackie Cooper, American actor (b. 1922)
- May 7
- May 9 – Lidia Gueiler Tejada, 67th President of Bolivia (b. 1921)
- May 16 – Samuel Wanjiru, Kenyan athlete (b. 1986)
- May 19 – Garret FitzGerald, 7th Taoiseach of Ireland (b. 1926)
- May 20 – Randy Savage, American professional wrestler (b. 1952)
- 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, Flemish Belgian writer and revolutionary political activist, noted for his work on francophone Africa and the Soviet Union (b. 1946)
- June 7 – Jorge Semprún, Spanish writer and politician (b. 1923)
- June 9
- June 10 – Patrick Leigh Fermor, British travel writer, scholar and soldier (b. 1915)
- June 18
- June 23 – Peter Falk, American actor (b. 1927)
- 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 10 – Roland Petit, French choreographer and dancer (b. 1924)
- July 12 – Tom Gehrels, American astronomer (b. 1925)
- July 17 – Juan María Bordaberry, 36th President of Uruguay (b. 1928)
- July 20 – Lucian Freud, German-born British painter (b. 1922)
- July 23
- July 25 – Mihalis Kakogiannis, Cypriot filmmaker (b. 1922)
- 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 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 19 – Raúl Ruiz, Chilean film director (b. 1941)
- August 22
- August 31 – Valery Rozhdestvensky, Soviet-Russian cosmonaut (b. 1939)
- September 7 – Victims of the 2011 Lokomotiv Yaroslavl air disaster
- Vitaly Anikeyenko, Ukrainian-Russian hockey player (b. 1987)
- Mikhail Balandin, Russian hockey player (b. 1980)
- Gennady Churilov, Russian hockey player (b. 1987)
- Pavol Demitra, Slovakian hockey player (b. 1974)
- Robert Dietrich, Kazakhstani-German hockey player (b. 1986)
- Marat Kalimulin, Russian hockey player (b. 1988)
- Alexander Kalyanin, Russian hockey player (b. 1987)
- Alexander Karpovtsev, Russian hockey player (b. 1970)
- Andrei Kiryukhin, Russian hockey player (b. 1987)
- Nikita Klyukin, Russian hockey player (b. 1989)
- Igor Korolev, Russian hockey player (b. 1970)
- Stefan Liv, Polish-born Swedish hockey player (b. 1980)
- Jan Marek, Czech hockey player (b. 1979)
- Brad McCrimmon, Canadian hockey player (b. 1959)
- Sergei Ostapchuk, Belarusian hockey player (b. 1990)
- Karel Rachůnek, Czech hockey player (b. 1979)
- Ruslan Salei, Belarusian hockey player (b. 1974)
- Maxim Shuvalov, Russian hockey player (b. 1993)
- Kārlis Skrastiņš, Latvian hockey player (b. 1974)
- Pavel Snurnitsyn, Russian hockey player (b. 1992)
- Daniil Sobchenko, Ukrainian-Russian hockey player (b. 1991)
- Ivan Tkachenko, Russian hockey player (b. 1979)
- Pavel Trakhanov, Russian hockey player (b. 1978)
- Yuri Urychev, Russian hockey player (b. 1991)
- Josef Vašíček, Czech hockey player (b. 1980)
- Alexander Vasyunov, Russian hockey player (b. 1988)
- Alexander Vyukhin, Ukrainian-Russian hockey player (b. 1973)
- Artem Yarchuk, Russian hockey player (b. 1990)
- September 8 – Võ Chí Công, 5th President of Vietnam (b. 1912)
- September 10 – Cliff Robertson, American actor (b. 1923)
- September 11 – Andy Whitfield, Welsh actor and model (b. unknown)
- 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 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 22 – Aristides Pereira, 1st President of Cape Verde (b. 1923)
- September 25 – Wangari Maathai, Kenyan veterinary anatomist and Nobel Peace Prize laureate (b. 1940)
- September 27 – Imre Makovecz, Hungarian architect (b. 1935)
- September 30
- October 1 – Sven Tumba, Swedish hockey player (b. 1931)
- October 5
- October 6 – Diane Cilento, Australian actress (b. 1933)
- October 7 – Ramiz Alia, 1st President of Albania (b. 1925)
- October 12 – Dennis Ritchie, American computer scientist (b. 1941)
- October 16 – Dan Wheldon, English racing car driver (b. 1978)
- October 20 – Muammar Gaddafi, Libyan dictator (b. 1942)
- October 22 – Sultan, Crown Prince of Saudi Arabia, (b. 1930)
- October 23
- October 24 – John McCarthy, American computer scientist (b. 1927)
- October 29 – Jimmy Savile, English DJ, television presenter, media personality and charity fundraiser (b. 1926)
- October 31 – Flórián Albert, Hungarian footballer (b. 1941)
- November 4 – Alfonso Cano, Colombian militant leader (b. 1948)
- November 5 – Norman Foster Ramsey, Jr., American Nobel physicist (b. 1915)
- November 7 – Joe Frazier, American boxer (b. 1944)
- November 8 – Valentin Ivanov, Russian footballer (b. 1934)
- November 9 – Har Gobind Khorana, Indian-born American Nobel biochemist (b. 1922)
- November 21 – Anne McCaffrey, American writer (b. 1926)
- November 22 – Paul Motian, American jazz drummer (b. 1931)
- November 25 – Vasily Alekseyev, Soviet-Russian weightlifter (b. 1942)
- November 27
- November 28
- December 1 – Christa Wolf, German writer (b. 1929)
- December 4 – Sócrates, Brazilian footballer (b. 1954)
- December 5 – Violetta Villas, Polish singer (b. 1938)
- December 7 – Harry Morgan, American actor (b. 1915)
- December 8 – Sir Zelman Cowen, 19th Governor-General of Australia (b. 1919)
- December 14 – Joe Simon, American comic book writer and artist (b. 1913)
- December 15 – Christopher Hitchens, British-American writer (b. 1949)
- December 17
- December 18 – Václav Havel, Czech playwright, 10th President of Czechoslovakia and 1st President of the Czech Republic (b. 1936)
- December 24 – Johannes Heesters, Dutch actor and singer (b. 1903)
- December 27
- Chemistry – Dan Shechtman
- Economics – Christopher A. Sims and Thomas J. Sargent
- Literature – Tomas Tranströmer
- Peace – Ellen Johnson Sirleaf, Leymah Gbowee and Tawakel Karman
- Physics – Saul Perlmutter, Adam G. Riess, and Brian P. Schmidt
- Physiology or Medicine – Bruce A. Beutler, Jules A. Hoffmann, and Ralph M. Steinman