Ghost is a character appearing in American comic books published by Marvel Comics. Created by David Michelinie and Bob Layton, the character first appeared in Iron Man #219 (June 1987). Ghost is a genius inventor and hacker who wears a battle suit that allows him to become invisible and intangible. Although he started out as an adversary of the superhero Iron Man, Ghost has also been depicted as an antihero and member of the Thunderbolts.

The character has been substantially adapted from the comics into various forms of media, including animated television series and video games. Hannah John-Kamen portrays a gender flipped version of the character named Ava Starr in the Marvel Cinematic Universe (MCU) films Ant-Man and the Wasp (2018) and Thunderbolts* (2025). A reimagined version of the MCU Ghost made her comic debut in 2025.

Created by David Michelinie and Bob Layton, the character first appeared in Iron Man #219 (June 1987). Originally a supervillain to Iron Man, Ghost has since become an anti-hero figure after becoming a member of the Thunderbolts during the events of "Dark Reign" and "Heroic Age".

Ghost (real name unknown) once worked as a programmer and an engineer at the IT company Omnisapient. Impressing the board of directors with his technological prowess and genius intellect, he quickly rose up the ranks and assumed the company's flagship project for which he developed a revolutionary processor that could physically change in reaction to its environment, becoming intangible. Thanks to his Ghost Tech, the company's stock skyrocketed while the board collected the credit. Exhausted after months of work, Ghost decided to leave on vacation, conflicting with the board of directors' expectations for an ahead-of-schedule launch that could increase their profit margins significantly. Approached by his co-worker as he was about to leave, Ghost cancelled his travel plans and began a relationship with her. Happier and more productive than ever, he now found every single aspect of his life tied to the company until his lover died in an explosion at her apartment. Ghost sought solace by integrating his technology into his body, which he used to uncover that his lover had been hired by the board to seduce him and was murdered for blackmailing them. Terrified, Ghost attempted to flee, but his discoveries had been detected by the board of directors, who dispatched a contract killer after him. The hitman detonated a bomb in his apartment before he could leave, destroying the entire building and killing dozens of tenants. Ghost survived, becoming intangible via his technology. Ghost became a vigilante bent on wiping out corporatocracy. He took revenge upon the board of directors, butchering them, along with their contract killer, and erasing all records of his previous life.

Sometime after this, Ghost is hired by Carrington Pax, a leading executive of the Roxxon Oil Corporation, to destroy Accutech Research and Development. Accutech had been trying to develop a beta particle generator and when they refused to sell it to Roxxon, Ghost was hired to drive Accutech into bankruptcy. Tony Stark is interested in acquiring Accutech's technology and buys out the company. Investigating a disturbance at the new facility as Iron Man, he first encounters Ghost, who swears revenge against Stark. When Pax and the other executives at Roxxon learn that Ghost has gone rogue, they fear his actions would make the company look bad, so they hire Spymaster to take care of him. After a fierce battle at Stark Enterprises, Ghost kills Spymaster. Iron Man confronts Ghost in a room with a beta particle generator, which interferes with Ghost's suit and will prove fatal with prolonged exposure. As Ghost tries to reach the generator to destroy it, he falls through the floor and is presumed dead.

Ghost resurfaces plaguing a company in Italy, owned by Justin Hammer. The shrewd industrialist intended to sell the company, Electronica Fabbrizi, to Tony Stark, ridding him of a dangerous enemy and a useless asset. After Tony Stark discovers the true ownership of the floundering company, he agrees to work with Hammer to take down Ghost. When Ghost confronts Hammer, he learns that Hammer had developed defenses against Ghost's technology. After escaping, Ghost vows to continue his crusade against Hammer and other companies.

During the "Dark Reign" storyline, Ghost seems to have become more unhinged and reclusive. With the Thunderbolts officially disbanded, Norman Osborn recruits Ghost for his new Thunderbolts, now a black ops team under Osborn's direct control. Ghost betrays Osborn by sending a data package to whatever heroes could receive it, warning them of Osborn's plans to capture Odin's spear Gungnir. Aware of the emergency, Quicksilver crosses the Atlantic Ocean and retrieves Gungnir.

Because Tony Stark had purposely lobotomized himself into a vegetative state, and had his power of attorney transferred over to Donald Blake, Madame Masque hired Ghost to kill Stark. She provided him a phone made by the Tinkerer, which he could use to execute his phase abilities to reach any place in the world. Ghost managed to track Stark to Broxton, Oklahoma, where he twice attempted to assassinate Stark. All the while, Stark's comrades were attempting to reboot his brain. By then, Stark had regained consciousness and used Ghost's own phone against him, sending him to a facility in Seoul.