Omnipotence

There are different definitions for Omnipotence: The problems occur by asking questions like "Could God make a stone so heavy he can no longer lift it?" If he can't do it, then he is not omnipotent because he should be able to create such a heavy stone, if he can do it, then he is not omnipotent, because he can't lift the stone. There are many variations of the problem, for example: Could God create something stronger than himself ? As no character in the Supernatural Universe is omnipotent by either of these two definitions, no such problem has arisen on Supernatural.
 * The ability to do anything non-contradictory. This definition prevents logical contradictions.
 * The ability to do anything, this definition leads to logical contradictions.

Omnipotence
No entity in the Supernatural universe is truly omnipotent in the sense of the common definition of the word.

Nigh-Omnipotence
Entities of nearly unlimited power that can create conscious beings, new realities, or at least warp them to an unlimited extent.
 * Cosmic Entity (within the Empty) - Cosmic Entity is the supreme ruler of the Empty, a place of nothingness inhabited by every deceased angels and demons where they slumber for all eternity. The Entity has unrivaled control over it, even Heaven, Hell and God does not have authority on the Empty. Like the inhabitants of the Empty, the Entity itself sleeps for eternity and unlike them, it needs to sleep. If any being is awakened in the Empty, it affects the Entity and awakens it from the eternal sleep which causes it pain. Despite his complete authority over the Empty, the Entity cannot force a being to sleep.
 * Death - Death holds immense power which is far greater than Archangels. His power is so great that he can accomplish incredibly extreme feats of power such as flooding the earth, creating an eclipse by re-aligning the solar system and killing lesser beings with a mere touch. According to himself, he would reap God at the end of time. However, there are many things he can't do.
 * God - God possesses near-infinite power, being able to do almost anything that he desires. It is shown that he isn't fully omnipotent, as he can't instantly kill his older sister, the Darkness. However, through his own power, he was able to create beings who helped him defeat her, although barely. He also is said to have no power over the Empty and, according to Metatron, had to put in a degree of effort to manifest creation and couldn't have done it with a simple snap of his fingers. Being almost omnipotent, he also has the ability to grant himself more abilities, among those were the ability to speak French and play guitar.
 * The Darkness - The Darkness is the most powerful entity in existence, more powerful than God himself. The latter, her younger brother, stated that even with all four archangels fighting against her the first time, along with himself, victory was barely achieved. Even after withstanding a combined but sequential attack by powerful supernatural beings during a second confrontation, she still proved to be stronger than God when she stopped him from trapping her again, overpowered Lucifer at the same time, and fatally wounded her brother, all before regenerating fully and walking away. Not long after, upon reconciling with God, Amara was able to heal the fatal damage her nigh-omnipotent powers did to him, without any difficulty.
 * Jack (formerly; power replenishing) - As the Nephilim child of Lucifer; the second born archangel, Jack possesses unimaginable power. According to Sam Winchester, his powers will surpass those of even Lucifer. Initially, Jack, as a newborn Nephilim, did not have much understanding of his powers and therefore could not control them. He was able to telepathically awaken an angel sleeping in the Empty unintentionally, which was impossible according to Entity controlling the Empty who was surprised and confused to see an awake being. The Entity also stated that God himself does not have power over the Empty, implying that Jack may be even stronger than his grandfather. He also later destroyed an entire army of angels in the Apocalypse World, led by Balthazar, not only proof of how much power he possesses but that he now has control and use over most of his power. Later he was easily able to inflict painful damage to Michael, most likely meaning that his power had grown into Nigh-Omnipotence (as no other being aside from God and The Darkness have shown capable of easily inflicting such damage to an archangel). However Lucifer stole a Jack's Grace rendering him powerless. Castiel confirmed that Jack's powers are not truly gone and would return to him in time. However, It has been stated that his Grace may take a long time, between a month and a century to recharge and his human heritage is slowing it down. Additionally, none of Jack's power has been confirmed to have returned to him as he has not yet shown any of his former powers.
 * Lucifer (after consuming Jack's Grace) - As the second-born archangel Lucifer was already extremely powerful, and after consuming most of his son's grace, the Apocalypse World Michael described him of being powerful enough to destroy and remake the universe in a matter of days. However Dean, while using the powers of the Alternate Michael was able to challenge him, only losing partially due to Lucifer having much greater fighting skills.
 * Castiel (temporarily; while empowered by purgatories souls) - Castiel's powers were exponentially magnified as a result of having absorbed all the souls from Purgatory. At this level of power, Castiel could annihilate lower Archangels with a snap of his fingers and (supposedly) erase Hell from existence. However, despite his newfound power, he was still keen on keeping Michael and Lucifer locked in the Cage.

Lower Tier Nigh-Omnipotence
Entities of nearly unlimited power that are weaker than the top tier.
 * Archangels - Archangels have a tremendously vast supply of power, they can accomplish incredible feats of power such as obliterating and banishing common Angels with gestures, finger snaps, winks or even simple thoughts. However, there is still much that they can't do: find humans who are protected by enochian sigils, forced possession of a vessel, or breaking out of Lucifer's cage.
 * Metatron (temporarily; while connected to the Angel Tablet) - Empowered by the Word of God, his angelic powers were greatly enhanced and common angelic weaknesses such as holy fire proved to be ineffective against him.


 * Jesse Turner - Fueled by Lucifer's presence on Earth, Jesse has accomplished incredible feats of power such as exorcising a demon by verbally telling them to leave their host, turning an Angel into a figurine, conjure beings into existence simply by believing in them, etc. According to Castiel, at the peak of his power, Jesse would have been able to destroy the entire host of Heaven with a single word. After Lucifer's death, it is unknown if he is permanently powerless.