- "I'll be damned... the prodigal son returns."
- ―Tony Stark
The Mark XLII Armor was Tony Stark's forty-second Iron Man suit and was built to serve as his main Iron Man armor following the Battle of New York and the construction of the Iron Legion. Designed for automatic deployment and assembly, the suit is composed of several separate sections that can collapse into small pods. Using an independent propulsion system, each section can fly to the user and automatically assemble on their person. The suit can be summoned at any time, responding to impulses relayed by microchips implanted in Tony Stark's left arm.
The Mark XLII never became finalized, as it was still in its testing phase when Stark was forced to start using it, thus it retained some design flaws in the weapons system and other functions.
Tony Stark built the Mark XLII a few months after the Battle of New York. It was first used in action when the Mandarin attacked his house. Stark used the suit to mentally suit Pepper Potts up in it to protect her fall in the explosions. Pepper then made her way out of the mansion with Maya Hansen. When Pepper was clear of the explosions, Stark suited himself up in the Mark XLII.
Since it was at 22% power, Stark had a difficult time defending himself. Nonetheless, he still managed to take down two of the three assault helicopters that were attacking. However, when he destroyed the second chopper, it came flying at him, sending Stark into the water.
Stark fell unconscious, but his AI system - J.A.R.V.I.S. - helped him escape and flew them to Tennessee, following a flight plan from his investigation on the Mandarin. His armor lacked enough power to fly back to California and the world believed him to be dead. It was later repaired and recharged and used to save Stark from the Mandarin's compound and to save Air Force One from the rogue Eric Savin's attack, before falling out of commission again. Later, in the battle against the Mandarin, it responded to Stark's anxiety and flew to him shortly after the Mark XL's destruction.
It was used by Stark to trap Killian against a wall. In an attempt to kill Aldrich Killian, Stark had J.A.R.V.I.S. activate the Mark XLII's self-destruct. The resulting explosion was so powerful that it destroyed most of the oil platform and ripped through the Mark XLII.
The Mark XLII Armor is undoubtedly one of the most unique and most powerful suits Stark has developed. Due to a series of computer chips he has implanted in his arms, Stark can summon the armor, as well as place the armor on others, with a simple gesture. He can mentally command the suit remotely with the aid of a Telepresence Headset. Unfortunately, it is very unstable and crashes several times due to still being a prototype armor. This suit also has qualities based on the Mark V and Mark VII that helped with the armor's portability. 
- In Iron Man 3, the suit had some malfunction in the weaponry, except the repulsor capability when he fought Mandarin's helicopters.
| Mark I • Mark II • Mark III • Mark IV • Mark V • Mark VI • Mark VII|
Mark VIII • Mark IX • Mark X • Mark XI • Mark XII • Mark XIII • Mark XIV • Mark XV • Mark XVI • Mark XVII •
Mark XVIII • Mark XIX • Mark XX • Mark XXI • Mark XXII • Mark XXIII • Mark XXIV • Mark XXV • Mark XXVI •
Mark XXVII • Mark XXVIII • Mark XXIX • Mark XXX • Mark XXXI • Mark XXXII • Mark XXXIII • Mark XXXIV •
Mark XXXV • Mark XXXVI • Mark XXXVII • Mark XXXVIII • Mark XXXIX • Mark XL • Mark XLI
Mark XLII • Mark XLIII • Mark XLIV/Veronica • Mark XLV • Mark XLVI • Mark XLVII
|Mark I • Mark II/Iron Patriot • Mark III|
|Mark I • Mark II|