- Jan 14 Tunisian president Ben Ali, flees to Saudi Arabia after popular protests known as the Jasmine Revolution
- Jan 25 Egyptian Revolution of 2011 begins with a series of street demonstrations, marches, rallies, acts of civil disobedience, riots, labor strikes and violent clashes in Cairo, Alexandria and other major cities
- Feb 11 Egyptian Revolution culminates in the resignation of Hosni Mubarak and the transfer of power to the Supreme Military Council after 18 days of protests.
- Mar 11 9.0 magnitude earthquake strikes 130 km (80 miles) east of Sendai, Japan, triggering a tsunami killing thousands of people and causing the second worst nuclear accident in history
- Apr 19 Fidel Castro resigns from the Communist Party of Cuba's central committee after 45 years of holding the title.
- May 2 Osama bin Laden, the suspected mastermind behind the September 11 attacks and the FBI's most wanted man is killed by United States special forces in Abbottabad, Pakistan.
- Jul 22 Norway is the victim of twin terror attacks, the first a bomb blast targeting government buildings in central Oslo, second a massacre at a youth camp on island of Utøya
- Sep 22 CERN scientists announce their discovery of neutrinos breaking the speed of light
The world population reaches 7 billion inhabitants according to the United Nations
On October 31, 2011