Galactus is a cosmic entity operating on a scale that dwarfs even the King of the Monsters.
Godzilla is the King of the Monsters โ a towering nuclear-powered kaiju with devastating atomic breath and incredible durability. But Galactus is a cosmic entity who eats entire planets for sustenance. The scale difference is not just large; it is categorical.
Godzilla's most powerful attacks are city-to-island level in most incarnations. Even the most powerful versions of Godzilla, including the Earth version or composite Godzilla, operate at planetary scale at most. Galactus routinely consumes entire planets and has destroyed star systems as collateral damage. His Power Cosmic allows him to manipulate matter and energy at a molecular level.
Godzilla's nuclear absorption abilities and incredible tenacity make him one of fiction's most durable monsters, but Galactus could simply consume the energy that powers Godzilla, drain his radiation, or transmute him at a molecular level. The Devourer of Worlds has countless ways to end this fight without throwing a single punch.
Galactus devours planets as sustenance and wields the Power Cosmic, which can manipulate matter and energy at a molecular level. He could consume Godzilla's nuclear energy or simply transmute the kaiju into harmless matter.
Godzilla has survived nuclear weapons, asteroid impacts, and attacks from other kaiju. His atomic breath can devastate cities, and his regeneration and durability have let him survive seemingly lethal encounters repeatedly.
Galactus wins this without significant effort. Godzilla is mighty by Earth standards, but Galactus operates at a cosmic scale that makes even the King of the Monsters irrelevant.
Galactus also fights
Godzilla also fights