January 1:
- The Euro is launched as the currency for 11 European countries.
March 24:
- NATO begins bombing of Yugoslavia in response to the ongoing Kosovo War.
April 17:
- Kosovo War: Serbian forces massacre Albanian civilians in the town of Račak.
May 7:
- The impeachment trial of U.S. President Bill Clinton begins in the Senate.
May 12:
- The Yugoslav Wars end as NATO signs an agreement with Serbia.
June 1:
- Swissair Flight 111 crashes into the Atlantic Ocean, killing all 229 people on board.
July 20:
- The Columbine High School massacre occurs in Colorado, United States, resulting in the deaths of 13 people.
August 17:
- A powerful earthquake measuring 7.4 on the Richter scale strikes Turkey, killing over 17,000 people.
October 27:
- Armenia and Azerbaijan sign a cease-fire agreement to end the Nagorno-Karabakh conflict.
December 10:
- The Seattle World Trade Organization (WTO) conference begins amid widespread protests against globalization.
December 20:
- Portugal transfers sovereignty of Macau back to China, ending its colonial presence.
December 31:
- Boris Yeltsin resigns as President of Russia, passing power to Vladimir Putin.
- The world enters the year 2000, marking the start of the new millennium.