In Greek mythology and history, Xanthus ("yellow"; also Xanthos) is the name of several individuals and creatures.

• Xanthus is the name of one of Achilles' horses; see Balius and Xanthus.
• Xanthus is one of the Mares of Diomedes.
• Xanthus is a son of Phaenops who was killed by Diomedes.
• Xanthus is the name of one of Hector's horses.
• Xanthus is the gods' name for Scamander.
• Xanthus was a Theban king, the son of Ptolemy. He was killed by Andropompus or Melanthus.
• Xanthus was the son of Erymanthus and father of Psophis.
• Xanthus was a son of Pan who was allied with Dionysus.
• Xanthus was the lover of Alcinoe, who left her family to be with him.
• Xanthus was a king of Termera.
• Xanthus was a son of Aegyptus; he married Arcadia, one of the Danaids.
• Xanthus was a logographer who wrote a history of Lydia.

Xanthus is the name of Aristotle Bolt's estate in the 1975 Disney movie Escape to Witch Mountain.