Xystus has several meanings:

• Xystus, a Greek architectural term denoting the covered portico of a gymnasium
• Xystus, another spelling for the Roman name Sixtus
• Pope Xystus I
• Pope Xystus II
• Pope Xystus III
• Xystus, a Greek student of Pythagoreanism with whom the authors of the Liber Pontificalis perhaps conflated with Xystus I
• Xystus, a taxonomic synonym of Alloxysta, a genus of wasps
• Xystus (weevil), a genus of beetles in the tribe Apostasimerini

See also: Sixtus of Reims

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