Odin is the son of Bor (father, one of the first Asgardians) and Bestla (mother, a frost giantess). Bor and Bestla also have two other sons, Vili and Ve. He claims to have created humans as he felt the world was lonely. But his father was angry and created things to plague humanity. With the aid of his brothers, a young Odin battles and defeats the fire demon Surtur. Many millennia later, Odin would reveal the origin of his powers and the eventual fate of his brothers; they were killed by Surtur, but gave their power to Odin. Later Surtur was imprisoned inside the Earth for centuries by Odin after forming an alliance with the trolls. Odin becomes ruler of Asgard, and due to his vital link to the realm, came to be known by the epithet of All-Father, and eventually falls in love with Gaea, in time becoming the father of the Thunder God Thor as he wanted a son who would be strong on both Asgard and Earth. He creates a cave in Norway in which Gaea gives birth. He notices that Thor's eyes are those of Bor, and realizes one day 'the wheel will turn again'. He then returns to Asgard with Thor, where his wife, Frigga, acts as Thor's mother. Odin is also the adoptive father of Loki, a child of Giant blood whose father King Laufey is killed by Odin in battle. Odin adopted Loki as part of a deal with his father Bor's spirit so that Bor would stop haunting him for replacing him, unaware that Bor's intention was that the child would bring about his son's downfall. Despite Odin's best intentions, his sons become bitter enemies, with the feuding often requiring Odin's mediation. Odin also was the father of Balder by the way of Frigga; thus, Balder is a half-brother to Thor.
Thor's preoccupation with Midgard (the Asgardian term for Earth) is a constant annoyance for Odin who, as punishment, has taken Thor's powers on at least three occasions. Thor's acceptance of the sanctions, along with his willingness to atone for his transgressions, his continued noble intentions, and his bravery, eventually convince the All-Father to relent and thereby restore Thor's original powers and identity. Once, he saved Asgard by threatening to draw the Odinsword when Seldring stole the Odin Force, as Odin had briefly given it to him to strip Thor of half his power. But Seldring had refused to return it after depowering Thor and planned to rule Asgard.
As ruler and protector of the Asgardian people, Odin has been involved in a number of crises that have threatened Asgard and, on occasion, Earth. Notable examples included stopping Loki, the Storm Giant Skagg, and Surtur (with the aid of Thor and Balder); defeating the Absorbing Man after he absorbs almost all of Asgard; banishing the monster Mangog; sacrificing his right eye to Mimir for the wisdom to stop Ragnarök (Twilight of the Gods); attempting to stop the Celestials in the armor of the Destroyer; engaging inter-dimensional tyrant Dormammu in a "cosmic chess" match as champions of Master Order and Lord Chaos respectively, and preventing Surtur from lighting the Sword of Doom.
Odin has also died three times in defense of Asgard. On the first occasion, Odin is killed by Mangog, although he is later revived by the goddess of Death Hela to prevent Pluto from claiming him. On the second occasion, the Celestials melt the Destroyer to slag, which at the time holds the life force of Odin and all Asgardians with the exception of Thor. Thor, however, collects a portion of godly energy from each pantheon and uses it to revive Odin, who in turn resurrects the Asgardians.
The final occasion involves a massive battle against arch-foe Surtur on Earth, with Odin apparently dying once and for all, as the Odin Force—the source of Odin's power—migrates to his son, Thor. As Thor eventually destroys the Loom of Fates and stops Asgard from perpetuating Ragnarok—which ends the entire Norse pantheon and Asgard itself—Thor believes Odin may be dead permanently. The Odin Force appears to him in humanoid form and says that this was Odin's plan all along: that he break the cycle.
When Thor returns from hibernation in the void, he begins to find the lost Asgardians, and although successfully restoring them all, does not attempt to find his father. During the Odinsleep, Thor has a vision in which he discovers that on a subconscious level he does not do so as he wishes to be free of his father. Also during his Odinsleep, Thor does find Odin in a limbo between life and death, where every day he does battle with Surtur to prevent the demon from reentering the world. They each die in the battle, but are resurrected to battle again. Odin declines Thor's offer of taking his place—noting that just Thor's offer has broken Bor's curse that he would be abandoned as Bor was—and states that Thor must continue to lead the Asgardians, recognizing his son's ability to see a path beyond the path and cycle of Ragnarok that Odin lacks, while Odin continues to exist in a state he describes as approximating the Asgardian equivalent of heaven in order to prevent Surtur from reentering the world. Loki assuages Doom's fears about Odin's potential wrath if the Asgardians were to move to Latveria, assuring him that "Old One-Eye is yesterday's god" and "a relic". Later, it is Odin's absence from the Nine Worlds that led his revived father Bor to believe that he had been slain in combat with the Frost Giants, spurring him to wage battle against Thor, in which he is killed, leading to Thor's exile for killing someone who was officially the King.
Norman Osborn sends the Thunderbolts to steal Odin's spear from the Asgardian weaponry. Loki calls on Odin to return the Norn Stones to him so he can empower the heroes to defeat the Void.
Odin returns from the dead after Asgard is invaded by the World-Eaters.
Odin senses the return of Serpent: God of Fear. After a brief monologue with Uatu the Watcher, Odin commands his people to return to the Asgardian plane against the protests of Thor (whom Odin has chained and forcefully dragged there against his will). Odin builds up Asgard into a war engine with which he intends to raze Earth completely in order to destroy the Serpent. Thor (who is freed by Loki and joined by his loyal comrades) opposes Odin's plan to destroy the Earth, and convinces Odin to send him back there, but Odin tells him that he has only until the shadow of the Serpent falls upon the world tree before his plans to raze Earth become inevitable. Iron Man travels to Broxton to the portal that leads to Asgard-space demanding an audience with Odin. Iron Man asks Odin if he can use one of Asgard's workshops in order to make weapons to fight the Worthy. After being convinced by Iron Man, Odin allows him to use the Workshops of Svartalfheim where he convinces the Dwarves there to help him with weapons that might help stop the Serpent before his shadow falls onto the World Tree. Captain America and the Avengers bring an unconscious Thor to Broxton so that they can have Odin heal Thor. As Odin tends to his son's wounds, he tries to convince Thor he should not suffer a conflict that is Odin's fault, but Thor continues to insist against destroying Earth to save Asgard. Odin prepares Thor by giving him the armor and helmet that he himself wore the last time he cast out the Serpent and slaughtered the billions stained by his sickness. He also gives Thor the Odinsword named Ragnarok (which was forged to end all things). Despite this, Odin gives Thor a final chance to avoid another battle with the Serpent asking him if he is a god or a man. Thor responds that he is a man, the one Odin raised him to be. While Thor kills the Serpent at the cost of his own life, Odin frees those affected by the Hammers of the Worthy by summoning their hammers away from them. Odin returns to Asgard with the corpse of the Serpent sealing off Asgard from Hermod and a number of other Asgardians who are left on Earth.