XII may refer to:

• 12 (number) or XII in Roman numerals
• 12th century or XII in Roman numerals
• XII (album), an 2012 album by American country music singer Neal McCoy.

12 (twelve ) is the natural number following 11 and preceding 13. The product of the first three factorials, twelve is a superior highly composite number, evenly divisible by 2, 3, 4, and 6. It is central to many systems of counting, including the Western calendar and units of time, and frequently appears in the Abrahamic religions.