The name or term "Gaius" may refer to:
Characters
- Erikon Gaius — An Ultramarines Captain.
- Gaius (Apothecary) — An Ultramarines Apothecary.
- Gaius (Blood Angels) — A Blood Angels Captain.
- Gaius (Captain) — An Ultramarines Captain.
- Gaius (Chaplain) — An Ultramarines Chaplain.
- Gaius (Magos) — An Explorator of the Adeptus Mechanicus.
- Gaius (Unnumbered Sons) — A Primaris Space Marine.
- Gaius Acastian — A Deathwatch Watch Master.
- Gaius Aquilius — A White Consuls Captain.
- Gaius Hadraichus — A Novamarines Chapter Master.
- Gaius Pollandus — An Ultramarines veteran.
- Gaius Prabian — An Ultramarines Champion.
- Gaius Rhacelus — A Blood Angels Epistolary.
- Gaius Theodos — An Imperial Fleetmaster.
Other
- At Gaius Point — A short story by Aaron Dembski-Bowden.