Ant-Man is the name of several superheroes appearing in books published by Marvel Comics.

Created by Stan Lee, Larry Lieber and Jack Kirby, his first appearance was in Tales to Astonish #27 (January 1962) as Dr. Henry Pym; however, he first appeared in costume as Ant-Man in Tales to Astonish #35 (September 1962). The persona was originated by the brilliant scientist Hank Pym's superhero alias after inventing a substance that can change size (Pym Particles), but reformed thieves Scott Lang and Eric O'Grady also took on the Ant-Man mantle after the original changed his superhero identity to various other aliases, such as Giant-Man, Goliath, and Yellowjacket. Pym's Ant-Man is also a founding member of the super hero team known as the Avengers.

Over the years, a number of different characters have assumed the title of Ant-Man; most of them have been connected with the Avengers.

Dr. Henry "Hank" Pym was a biophysicist and security operations center expert who decided to be the original Ant-Man, a superhero after the death of his first wife Maria Trovaya who had been a political dissident in Hungary. Falling in love with him and believing that his American citizenship would protect her, Maria traveled with Hank to Hungary shortly after their marriage to start their new life together. Unfortunately they were confronted by corrupt agents of the secret police. Hank was knocked unconscious and Maria was murdered. Pym was greatly distraught by his wife's death, and decided to do whatever he could in the future to battle injustice. After discovering a chemical substance, which he called Pym Particles, that would allow the user to alter his size, he armed himself with a helmet that could control ants. After that, Pym would shrink down to the size of an insect as the mystery-solving Ant-Man, solving crimes and stopping criminals. He soon shared his discovery with his second wife Janet van Dyne as his crime-fighting partner Wasp when he helped Janet avenge the death of her scientist father Vernon van Dyne who was killed by an alien unleashed by one of Vernon's own experiments. The duo would be founding members of the Avengers, fighting recurring enemies such as the mad scientist Egghead, the mutant Whirlwind, and Pym's own robotic creation Ultron. While Pym is the original Ant-Man, he has adopted other aliases over the years including Giant-Man, Goliath, Yellowjacket, and Wasp after Janet's presumed death in Secret Invasion. Leaving his original persona vacant, his successors have taken up the Ant-Man role while Pym explored these other identities.

Scott Lang was a thief who decided to be the second Ant-Man after stealing the Ant-Man suit to save his daughter Cassandra "Cassie" Lang from a heart condition. Reforming from his life of crime, Lang soon took on a full-time career as Ant-Man with the encouragement of Hank Pym. He became an affiliate of the Fantastic Four and later became a full-time member of the Avengers. For a period of time he dated Jessica Jones. He was killed by the Scarlet Witch along with the Vision and Hawkeye in Avengers Disassembled, and his daughter took up his heroic mantle as Stature in the book Young Avengers. He returned to life in 2011 in the miniseries The Children's Crusade.

Chris McCarthy was the third character to take up the Ant-Man title albeit briefly, serving only as a plot point to get the Ant-Man suit to Eric O'Grady. The character, created by Robert Kirkman and Phil Hester, first appeared in Civil War: Choosing Sides #1 (October 2006). A low level agent of S.H.I.E.L.D. working on the Helicarrier, McCarthy was tasked with guarding Hank Pym's lab. After panicking and accidentally knocked Pym unconscious, he found the most recent Ant-Man suit which he promptly used to shrink, getting lost. McCarthy was caught up when a group of Hydra superhumans attacked and was killed in the chaos.

Eric O'Grady was the fourth character to take up the Ant-Man title. O'Grady is a low-level agent of S.H.I.E.L.D. who stumbles upon the Ant-Man suit. A man of few morals and willing to lie, cheat, steal and manipulate in order to get ahead in life, O'Grady stole the armor for his own selfish plans, which included using his status as a "super-hero" to seduce women, as well as humiliate and torment others. He had his own short-lived title before being part of other teams such as joining Avengers: The Initiative as his first team and then joining the Thunderbolts before the character perished heroically while defending a child against the villain known as Father.

Criti Noll was a Skrull who impersonated Hank Pym / Ant-Man during occasions before the Secret Invasion storyline.