XIII is the fourth studio album by American heavy metal band Mushroomhead, released on October 14, 2003.

The track "Sun Doesn't Rise" was also featured on the Freddy vs. Jason soundtrack.

The album received positive reviews, with critics stating that it was an improved version of XX.

British copies of the album include the song "Treason" and the instrumental "Loop #6".

Enhanced copies were said to have "Along the Way" and "Simpleton" as bonus tracks available for download through a CD identification process from a secret page on Universalmotown.com.