In the Ultimate Marvel continuity, Bobby Drake is the youngest founding member of the X-Men. He ran away from his family at the peak of government-supported Sentinel attacks, fearing his family would be killed in such an attack.
Ultimate Iceman never had the snowman look of his counter-part, instead generating a flexible ice armor from the beginning and still does so to this day. Bobby establishes himself as a valuable asset, single-handedly taking out the Ultimates once with a gigantic ice wall (see Ultimate War), as well as single-handedly halting an invasion by Colonel Wraith and Weapon X. He was only able to be stopped by Rogue, who was in temporary possession of Marvel Girl's telepathy. Professor X has stated that Bobby is one of the three most powerful X-Men. During the World Tour arc, after enlarging his armor to form a gigantic ice troll, Bobby is greatly injured by Proteus, which resulted in a lawsuit issued by his parents against Xavier. Bobby eventually rebels against his parents, and later returns to the X-Men.
Before Bobby joined the X-Men he had a girlfriend, but Professor Xavier erased all memories of her from Bobby's mind when he told her too much about the X-Men (he presumably also erased the girl's memories). Upon her acceptance into the X-Men, Bobby begins to date Rogue. The pair date for a considerable amount of time, but eventually break up due to Bobby's growing feelings for Shadowcat and Rogue's feelings for Gambit. Eventually Rogue leaves, and Bobby starts to date Kitty until she dumps him after finding Bobby was still emailing Rogue. When Rogue returned to the X-Men, her original powers had been replaced with those of Gambit's. During the Date Night arc, Bobby and Rogue have sex with one another (the first time for both of them), due to her being able to touch him now. After this, the two rekindle their relationship, but recently problems have erupted due to the return of Rogue's old powers.
Though Ultimate Iceman is still somewhat clumsy at present, the Ultimate version of Hammer, who hailed from the future, exclaimed upon meeting and subsequently battling him: "Bobby Drake, huh? The Legend! I can't believe you're so inept at this point in your life! It's been an honour to kick your..." only for Wolverine to interrupt him. Bishop also hinted to Bobby that he has a lot of potential, but Iceman shrugs off the acknowledgment.
In Ultimate X-Men #80, Bishop talks to Bobby about his potential and comments "With minimal effort you are taking moisture out of the air and slowing water molecules down to make them cold. What else can you slow down?" While this description is different in wording than that of his 616 counterpart, thermal energy is fundamentally the vibration speed of molecules. Faster vibrations equate to higher temperatures, so Bishop's explanation is essentially no different from the classic Iceman's mutant abilities. He also asks Bobby about exploring the possibilities with his powers, but Bobby merely shrugs him off and continues to play his video game.