Advanced Idea Mechanics or AIM - A techno-based terrorist group that splintered from its mother group, HYDRA. The group is often led by the conniving cyborg MODOK.
Blizzard - A costumed villain with a suit that enables him to produce ice and cold.
Blacklash - A weapons expert who brandishes a specially designed whip as his signature weapon.
Crimson Dynamo - A Soviet supersoldier clad in powered armor.
Crusher - A South American scientist who created the "Crusher" Formula which enabled him with super-strength, dense skin, and a weight of 1000 lb.
Dreadknight - A disfigured scientist with a vendetta against Iron Man and Doctor Doom.
Fin Fang Foom - Alien dragon from the planet Maklu IV.
The Ghost - A professional saboteur who's determined to kill Tony Stark and destroy Stark Enterprises.
Grey Gargoyle - A costumed villain who can turn anything he touches into stone.
Immortus - A master of time itself and future version of Kang the Conqueror, Immortus was responsible for manipulating Iron Man into various acts of villainy (including murder) against the Avengers during the controversial storyline, "The Crossing".
Iron Monger - Obadiah Stane, the business executive who stole Stark Enterprises from Tony Stark.
Justin Hammer - A businessman and rival of Tony Stark. He often pays superpowered "baddies" to sabotage Stark Enterprises. His daughter, Justine, is the villainess the Crimson Cowl.
Living Laser - A laser expert who eventually evolved into a being made of pure light energy.
Madame Masque - The daughter of Count Nefaria, she hides her scarred face behind a golden mask. She often has conflicted loyalties between her father and her lover, Iron Man.
The Mandarin - Considered by many to be Iron Man's greatest foe, the Mandarin is a Chinese nobleman, scientist and former diplomat turned criminal mastermind. His true power comes from his superhuman mastery of the martial arts and ten rings of power he recovered from an alien spaceship.
Radioactive Man - A Chinese physicist who can manipulate radiation.
Roxxon Oil (a corporation) - A major business rival of Stark Enterprises. They have a shady reputation and are constantly sending supervillains to sabotage Stark Enterprises.