| Tour by Slayer, Lamb of God, Mastodon, Children of Bodom, In Flames and Thine Eyes Bleed | |
 | |
| Start date | June 15, 2006 |
|---|---|
| End date | November 20, 2006 |
| Legs | 3 |
The Unholy Alliance Tour is a biennial heavy metal concert tour of Europe and North America, with the tag-line "Preaching to the Perverted". The tour is headlined by the thrash metal band Slayer, and featured Trivium, Amon Amarth and Mastodon in its latest edition.