Cajus may refer to:
*
Caius of Korea (1571–1624), Roman Catholic martyr
*
Cajus Schmiedtlein (c. 1555–1611), German composer and organist
* ''
Theretra cajus'', a moth of family Sphingidae
* The Latin praenomen
Gaius
Gaius, sometimes spelled ''Gajus'', Kaius, Cajus, Caius, was a common Latin praenomen; see Gaius (praenomen).
People
*Gaius (jurist) (), Roman jurist
*Gaius Acilius
*Gaius Antonius
*Gaius Antonius Hybrida
*Gaius Asinius Gallus
*Gaius Asinius Pol ...
, also spelled Cajus
{{Disambiguation, human name