Ithaki (ancient Ithaka) is said to have taken its name from the island's first settler, Ithacus, son of Poseidon and Amphimele. When he and his brothers, Neritus and Polyctor, grew up, they came to live on the island. Another myth has it that Ithacus was the son of Pterelaus and grandson of Taphius. Other experts believe that the name is from the Phoenician "Utica" (distant colony) or "Ithys" (cheerful, frank). the island's conquerors gave it various names, such as Nericie, Val de Compare (Valley of the Godfather), Fiaki, and finally Thiaki.

Its most important hero, however, was not Ithacus, but resourceful Odysseus, the most popular character in Greek mythology and one of the most famous and best-loved heroes in Homer's epics. Homer was a mythographer, and thus what he conveys lies somwehere between myth and reality.

Hermes and Chione, a nymph of snowy Mt. Parnassus, had a son, Aytolycus, who as he grew up proved himself adept at stealing and breaking oaths. At the same time another wily shepherd, Sisyphus, used to graze his sheep next to those of Autolycus. One would steal the other's sheep, until Autolycus was defeated in a contest of trickery. Then he got the idea that a son born to his daughter Anticleia and Sisyphus would inherit both his parent's cunning. Sisyphus, impatient to lie down with the fair maiden, didn't wait until his wedding night. Laertes asked for Anticleia's hand in marriage, when she had already become pregnant by Sisyphus (tragedies of Aeschylus, Sophocles and Euripides).

Another myth says that Odysseus was the lawful son of Laertes and Anticleia, and that he was born in the cave on Mt. Niritos because it was raining. Autolycus named his grandson Odysseus, that is, hated by everyone (as Homer interprets it in the Odyssey). After he grew up, he visited his grandfather on Mt. Parnassus, where his knee was injured during a wild boar hunt. Odysseus was sure Helen of Troy was going to choose him for a husband. But she chose Menelaus, and Odysseus took Penelope, daughter of Icarius and Periboea or Polycaste.

In the beginning, Odysseus did not want to take part in the Trojan War, but he was finally forced to. He fought heroically and revealed his crafty, resourceful character, particularly in the ruse of the Trojan Horse, which brought about the fall of Troy. But his adventures were not over when the war ended, because he had by that time provoked the wrath of several gods. The winds blew him to Thrace, where he overcame Ismarus. From there he headed south, to the Land of the Lotus-Eaters, where whoever ate the fruit of the lotus wanted to stay. Then he sailed to northern Sicily and the land of the Cyclopes. The Cyclopes were terrible man-eating giants with one eye in the middle of their foreheads. One of them, Polyphemus, son of Poseidon, would have eaten Odysseus and his men, if Odysseus and not got him drunk and blinded him. Bound to the underbellies of the giant's sheep, the prisoners tricked Polyphemus and escaped. This enraged Poseidon, and from that point on he was behind everything bad that befell Odysseus.

On the island of Aeolus, the god gave Odysseus the sack containing the winds; his curious companions, however, let loose the bad winds which blew them straight to the land of the man-eating Laestryogonians. Only one of Odysseus' ships was saved, which reached the island of Aeaea, where Circe lived. She was a sorceress who turned passing sailors into swine. When his companions didn't return to the ship, Odysseus went to see Circe himself. Hermes revealed her secret to him, and, after saving his companions, he stayed on the island for a month and had Telegonus by her. In the Land of the Cimmerians, the blind prophet Teiresias foresaw his future. Odysseus' next adventure took place near the island of the Sirens - women above the waist and birds below. With their superb singing they caused ships to run against the rocks and then ate the sailors. Odysseus stopped up the ears of his companions and tied himself to the mast. Then he passed the monsters Scylla and Charybdis who caused storms and devoured shipwrecked sailors. Odysseus' men persuaded him to put in at the island of Thrinacia. Unfavorable winds kept them there until some of them were so hungry that they slaughtered the sacred cattle of the Sun, who sank their ship, and only Odysseus survived. He landed on the island of Calypso, where he remained for years, until Zeus took pity on him and ordered Calypso to let him go. He built a wooden raft and after suffering Poseidon's wrath once again, he was washed up on the island of the hospitable Phaecians. He stayed with them for a short time and finally made it home to Ithaca. There Athena transformed him into a beggar and he went to his palace, where certain noblemen, the so called suitors of Penelope, were now living and squandering his wealth while they waited for her to choose one of them to marry. But she kept using various ruses to postpone making a decision. Odysseus appeared at the appropriate moment and killed them.

Homer's tale ends here, but tradition has given us two versions of Odysseus' death: one, that the relatives of the suitors forced him to leave the island, and he died in Tyrrenia in Italy at an advanced age, and the other that Teiresias' prophecy was fulfilled; Odysseus had to appease Poseidon by taking an oar and going to a country where where the people would ask him what it was he was carrying. There he was to sacrifice to Poseidon and then return home, but death would finally come to him on the sea. With regard to his death, Eugamon the Cyrenaean said that he dreamt his son would kill him, so he decided to exile Telemachus to Kefalonia. But his other son, Telegonus, arrived and plundered and ravaged the land until Odysseus tried to stop him. Telegonus killed his father with a spear tipped with a poisoned fish-bone.

The Olympian gods, particularly Athena, Hera, Apollo and his sister, Artemis, were worshipped in Ithaki.