Detroit Steel is a fictional suit of powered armor appearing in American comic books published by Marvel Comics, in which it is usually operated by adversaries or rivals of Iron Man. Created by writer Matt Fraction and artist Salvador Larocca, Detroit Steel first appeared in Iron Man (vol 5) #25 (June 2010) as part of the "Stark Resilient" storyline.

Detroit Steel first appeared in The Invincible Iron Man (vol 5) #25 (June 2010), the first part of the nine-part "Stark Resilient" storyline, which depicted Tony Stark's struggle to build his new company Stark Resilient, whose signature product is a car powered by the same clean repulsor technology that powers his Iron Man armor.

Writer Matt Fraction created Detroit Steel to embody jingoistic patriotism in the vein of Team America, and describes the character thus:

He is what follows in the hole left behind by Iron Man once Tony Stark leaves the world stage. Tony hasn't been around to protect the regular interests that he might have during his time running Stark Industries or running S.H.I.E.L.D. And now that he's back, he's made it clear he doesn't want to get back into the geo-political side of things necessarily. Detroit Steel is what happens in that absence. He is a sort of Blackwater-meets-NASCAR corporate-sponsored armored enhanced guy available for hire to the highest bidder for whatever cause around the round. Basically, Iron Man's worst nightmare of what he could become. An absolute perversion of everything he is.

Though the Detroit Steel armor exhibits the American flag's colors, Fraction states that the Detroit Steel armor can be repainted to reflect the colors of whatever country or corporation purchases them, from the Japanese Rising Sun Flag (which makes an appearance in The Invincible Iron Man #27) to the yellow and red colors of McDonald's. Fraction also contrasts Detroit Steel with Iron Man's Bleeding Edge armor, which debuted in the same issue, by describing the latter as "sleeker, slicker and pared down", whereas the former is "bigger and better and boisterous and loud and noisy and everything else. It's like the difference between a Porsche and a Mack Truck".

Former United States Air Force Lieutenant Doug Johnson III is the first pilot of the Detroit Steel armor, first appearing during the "Stark Resilient" storyline. He underwent surgical modifications in order to operate the weaponized suit, and also trained the other pilots in the Steelcorps army. Hammer Industries, led by Justine Hammer and Sasha Hammer, not only wish revenge on Tony Stark for their patriarch Justin Hammer's death, but see Stark as an obstacle for their product Detroit Steel which they hope to market globally as a new soldier for the world. Justine and Sasha embark on a campaign to discredit Iron Man in the industrial market, conspiring with the corrupt Pentagon General Babbage, and staging civilian attacks in which Detroit Steel is arranged to intervene before Iron Man. Shortly after, Detroit Steel launches a surprise attack on Stark Resilient by orchestrating a remote-server air-strike unwittingly piloted by young gamers on their mobile devices, who are unaware that their actions are affecting the real world. Iron Man, War Machine, Rescue and Maria Hill stop the strike and shut down Detroit Steel.

Detroit Steel next appears in The Invincible Iron Man during the 2011 storyline "Fear Itself". Detroit Steel is deployed in Paris and confronts Mokk, who is petrifying the population of Paris. However, Mokk attacks and petrifies Detroit Steel. In the subsequent "Demon" storyline, Johnson is revealed to be alive, but is believed to be dead by the public. In the subsequent "Long Way Down" storyline, Johnson kidnaps Sasha in order to steal a Detroit Steel unit, but is killed by Sasha.

The Detroit Steelcorps (otherwise known as the Steelmechs and Hammermechs) is a line of armored soldiers marketed by Hammer Industries.