5th Legion may refer to any of the following: Roman Legions * Legio V Iovia a Roman legion levied by Diocletian in the end of the 3rd century, and was still in service at the beginning of the 5th century. * Legio V Alaudae ("Lark-crested Fifth Legion"), sometimes also known as Gallica, was a legion of the Imperial Roman army founded in 52 BC * Legio V Macedonica one of the original twenty-eight legions raised by Octavian Other militaries