- “You can stop trying to read my mind, sugar. You're never going to get anything from me while I'm like this.”
- ―Emma Frost to Charles Xaviersrc
During the 1950s, Emma Frost was the mistress of Vinny Lavecchia, a Mafia boss based in Las Vegas, Nevada. Aware of her mutant abilities, Lavecchia used her telepathy in order to advance his career, eventually becoming the youngest boss in Nevada - with a significant influence around the Las Vegas strip.
One evening in 1959, Lavecchia visits the Hellfire Club, a small gambling establishment run by Sebastian Shaw in Las Vegas. Shaw had previously refused to pay Lavecchia insurance/protection money as per Mafia tradition. During a game with Shaw, Lavecchia suspects the former of swindling him, and calls for Emma in order read Shaw's intentions. To her surprise, she discovers that Shaw is a mutant - her first-time encounter with one. When Shaw once again refuses to pay, Lavecchia leaves in anger and quietly orders his men to kill Shaw. Shaw, however, escapes unscathed because of his mutant abilities, and soon makes plans to defeat Lavecchia and rescue Emma.
Back at his home, Lavecchia coerces Emma to reveal everything she gained from reading Shaw's mind in order to defeat him.
After Azazel and Riptide defeat the security detail around Lavecchia's home, Shaw attempts to "rescue" Emma. However, she knocks him out with a psychic concussive blast. Shaw is then taken to a remote warehouse.
At the warehouse, Lavecchia intends to kill Shaw by slowly cutting him into pieces - something that Shaw's kinetic energy absorption can't adapt to. Emma, however, begs that Shaw be dealt a quick death so as not to suffer. As Shaw implores Emma to abandon Lavecchia, the latter begins to physically abuse her. In defence, Emma converts to her diamond form, killing both Lavecchia and his bodyguard Santo in a rage.
Now convinced by Shaw's rhetoric of mutant superiority, Emma becomes associated with him and the Hellfire Club.
By 1962, Emma Frost was a full-fledged member of the Hellfire Club and one of Sebastian Shaw's most trusted allies. When CIA agent Moira MacTaggert was investigating the Hellfire Club in Las Vegas, she infiltrated a function Shaw was hosting disguised as one of Frost's dancers. While there, she witnesses Frost turn into her diamond form, which alerts MacTaggert to the existence of mutants and prompts her to contact Charles Xavier.
When Erik Lehnsherr came to kill Shaw aboard his yacht, she went into his mind, hurting him and then throwing him off the boat. She then escaped with Shaw into the submarine. She is shown Shaw's helmet the Soviets had given him and asks her to read his mind, she says that she can not while he is wearing the helmet. Shaw then tells her she is the most beautiful woman in the world, then says that his drink needs ice.
As Emma feels Xavier's telepathy expand, she looks to see whether he is close by and asks Azazel if there is anything on radar or sonar. After he says no, she tells Shaw about it. Shaw tells her to go to Russia while he takes care of the mutants at the CIA.
While in Russia, she uses her seduction skills to get the Russian General into bed. She then uses her telepathy to make the General believe that he and Emma are groping and kissing one another, with her sexually straddling him on his bed, wearing only her lingerie, but she is really sitting and eating crackers, watching him hugging and kissing the air. Xavier and Lehnsherr barge in and she turns into diamond form. She attempts to escape but Charles and Erik stop her and Erik makes the metal bed hold her. Magneto starts to crack her diamond form but Charles tells him to stop. Under the pressure, her diamond form starts to break but after the release, she goes back to normal form. She then gets sent to the CIA headquarters.
After the death of Shaw, Lehnsherr (now known as Magneto) starts his own team called the Brotherhood of Mutants and invites Emma to join after setting her free. Seeing her remaining Hellfire teammates with Magneto, she accepts.
Erik mentions that Emma Frost, along with Azazel and Angel Salvadore, had been killed in 1963 and blames Charles for their deaths. She was most likely among those experimented on and killed by Trask, since Mystique seeks revenge on Trask and a Sentinel is shown to use her powers.
- Organic Diamond Form - Emma possesses the ability to transform her body into a flexible organic diamond form. She can also selectively transform parts of her body into diamond. However, it is not invulnerable as Magneto was able to crack her diamond form by contracting metal bars around her neck.
- Enhanced Strength - Her diamond form allows her augmented strength. She is able to send Erik flying several yards off of the boat with a one handed push. She could be overpowered, however, by two people, as both Charles and Eric pulled her to the floor for Eric to restrain her with metal bars.
- Psychic Immunity - Emma has shown to be immune to other telepathic powers in her diamond form.
- Telepathy - Emma has displayed the telepathic standards of broadcasting and receiving thoughts, mind-control, and altering perceptions and memories.
- Psionic Blasts - Emma can produce telepathic blasts which can induce pain or knock out a person.
- Telepathic Communication - She is able to speak to the minds and was talking with Colonel Hendry.
- Telepathic Illusion - Also she can create realistic and powerful illusions which she uses to please the Russian General.
- It is unclear if she could be the same Emma Frost who appears in X-Men Origins: Wolverine. They appear to be two different characters, given that Emma Frost is significantly younger in Origins at a time when she should be older. Also, Emma Frost is said to have died between First Class and Origins. It is also notable that Emma from Origins does not exhibit the traditional telepathic abilities her First Class counterpart possesses; however, the official Blu-ray release for First Class confirms them to be the same character.