- Bizarro: A distorted, imperfect, and genetically altered clone of Superman. He possesses similar powers but tends to use them destructively.
- Brainiac: An advanced alien android with superior intellect and technology, often regarded as Superman's arch-nemesis next to Lex Luthor.
- Metallo: A cyborg with a radioactive heart, he poses a significant threat to Superman due to Kryptonite radiation affecting his powers.
- Doomsday: A mutated, indestructible, and incredibly powerful creature created by Lex Luthor, it nearly killed Superman in their first battle.
- General Zod: A Kryptonian warlord who leads a group of rebel Kryptonians against Superman. He possesses similar powers and challenges Superman's moral principles.
- Darkseid: The evil ruler of the planet Apokolips, Darkseid is an immensely powerful godlike being with advanced technology. He seeks to conquer Earth and the universe.
- Mongul: A warlord from the alien world of Warworld, Mongul possesses immense strength, durability, and ruthless determination to defeat Superman.
- Parasite: A human with energy-draining powers, he can temporarily absorb and redirect Superman's abilities, making him a dangerous adversary.
- Livewire: A former criminal turned energy manipulator, Livewire can generate and control electricity, posing significant challenges to Superman.
These are just a few notable enemies of Superman, highlighting the varied threats he faces from both Earth and beyond.