'''Xenology''' is a Warhammer 40,000 background book written by [[Simon Spurrier]]. It details all the main alien races of the Warhammer 40,000 universe, and some less well known ones. It features artwork including detailed dissections of the subjects investigated. It also includes some details of the [[Ordos Ordo Xenos]]. Xenology was published in 2006 and is now out of print.