This article is about the single year 1000; see 1000s, 990s, 10th century, 11th century for events or processes with "approximate date" 1000.

Year 1000 (M) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. It was also the last year of the 10th century as well as the last year of the 1st millennium of the Dionysian era ending on December 31st, but the first year of the 1000s decade.