Superman's speed gives him the edge, but Thor's magic-based powers exploit Supes' one weakness.
This cross-publisher clash is one of the most debated in comics, and it's been addressed directly in Marvel/DC crossovers โ with results that satisfied nobody.
Superman's primary advantage is speed. He can move and react at near-lightspeed, while Thor, despite being extraordinarily fast for an Asgardian, doesn't operate in that tier. This means Superman can land multiple blows before Thor can respond.
However, Thor has a critical trump card: Mjolnir's power is inherently magical, and Superman is vulnerable to magic. Thor's lightning isn't just electrical energy โ it's divine, enchanted power that bypasses Superman's normally impervious defenses. A direct hit from Mjolnir could genuinely hurt Superman in a way that few things in fiction can.
Strength-wise, they're comparable. Both have lifted objects of planetary mass, and both have limitless determination. The fight would be spectacular โ two of the most powerful heroes in all of comics, both refusing to stay down.
Superman's speed advantage is the deciding factor โ he can blitz Thor before the Asgardian can bring Mjolnir to bear. His heat vision offers a ranged option Thor can't easily counter at speed, and Superman's durability means even Mjolnir would need to land multiple solid hits. Superman also doesn't tire as long as yellow sunlight is available.
Mjolnir's magic-based attacks exploit Superman's greatest vulnerability. Thor's divine lightning, god-blast, and anti-force abilities could genuinely hurt the Man of Steel. Thor is also one of the most experienced warriors in fiction โ thousands of years of combat against cosmic threats. He's beaten Galactus-level enemies with Mjolnir's power fully unleashed.
Superman takes this more often than not due to his speed advantage, but Thor makes it a real fight. The magic vulnerability means every hit from Mjolnir actually counts, making this far closer than Superman's typical matchups. In a prolonged battle, Thor's magical arsenal could potentially overwhelm Superman's defenses.
Superman also fights
Thor (Norse) also fights