2000 : January - February - March - April - May - June - July - August - September - October - November - December

This is a timeline for events in October, 2000.

• October 4 - President Slobodan Milosevic leaves office after widespread demonstrations throughout Serbia and the withdrawal of Russian support.
• October 11 - 250 million gallons of coal sludge spill in Martin County, Kentucky. Considered a greater environmental disaster than the Exxon Valdez oil spill.
• October 12 - In Aden, Yemen, the USS Cole is badly damaged by two suicide bombers who placed a small boat laden with explosives along-side the United States Navy destroyer, killing 17 crew members and wounding at least 39.
• October 22 – Mainichi Shinbun exposes Japanese archeologist Shinichi Fujimura as a fraud.
• October 31 - Singapore Airlines Flight 6 collides with construction equipment in the Chiang Kai Shek International Airport - 83 dead.
• October 31 - The last Multics machine is shut down.