In contemporary history, the third millennium is a period of time that commenced on January 1, 2001, and will end on December 31, 3000, of the Gregorian calendar. This is the third period of one thousand years in the Common Era.

As this millennium is currently in progress, its first decade, the 2000s, is the subject of the historian's attention. The remaining part of the 21st century and longer-term trends are researched by futures studies.

Centuries and decades