Keuthonymos (or Ceuthonymus) (Κευθωνυμος) is the an ancient Greek spirit in mythology who is the father of Menoites (or Menoetes, Menoetius) who guarded the oxen of Hades. Keuthonymos is a mysterious Daimon or spirit of the Underworld, who lives in the realm of Hades. Keuthonymos is possibly the same as Iapetos, a Titan, and father of a certain Menoitios.
- Apollodorus (of Athens) (1921). Apollodorus: The library. W. Heinemann. p. 237
- Emily Vermeule (1981). Aspects of death in early Greek art and poetry. University of California Press. p. 242. ISBN 978-0-520-04404-3.
- Thomas Keightley (1896). The Mythology of ancient Greece and Italy. George Bell and Sons. p. 322.