In Greek mythology, Mentor (Greek: Μέντωρ / Méntōr; gen.: Μέντορος) was the son of Alcimus or Anchialus. In his old age Mentor was a friend of Odysseus who placed Mentor and Odysseus' foster-brother Eumaeus in charge of his son Telemachus, and of Odysseus' palace, when Odysseus left for the Trojan War.
When Athena visited Telemachus she took the disguise of Mentor to hide herself from the suitors of Telemachus' mother Penelope. As Mentor, the goddess encouraged Telemachus to stand up against the suitors and go abroad to find out what happened to his father. When Odysseus returned to Ithaca, Athena appeared briefly in the form of Mentor again at Odysseus' palace.
Because of Mentor's relationship with Telemachus, and the disguised Athena's encouragement and practical plans for dealing personal dilemmas, the personal name Mentor has been adopted in English as a term meaning someone who imparts wisdom to and shares knowledge with a less experienced colleague.