Legio XVIII ("Eighteenth Legion", spelled XVIII or XIIX) was a legion of the Imperial Roman army. It was founded ca. 41 BC by the future emperor Augustus. The legion was, along with Legio XVII and Legio XIX, destroyed in the Battle of Teutoburg Forest (September 9, 9 AD). The legion's symbol and cognomen are unknown. After their destruction, the Romans never used these legion numbers (XVII, XVIII and XIX) again.