Hall plays scientist Maya Hansen in the Shane Black-directed sequel, which will see Tony Stark on a vengeance mission against villains who have destroyed "his private world".
The actress recently discussed the experience of working with Black, explaining that the Kiss Kiss Bang Bang writer-helmer "has got a really wonderful understanding of pulp".
Ben Kingsley also joins the cast as the Mandarin, who is described as the most powerful foe Stark has ever faced.
Guy Pearce will also play a villain, while Gwyneth Paltrow and Don Cheadle reprise their roles as Pepper Potts and James Rhodes.
> Tony Stark 'traumatised' in Iron Man 3, says producer Kevin Feige
> Don Cheadle on 'Iron Man 3': 'Tony Stark is on an existential journey'
Iron Man 3 will be released on April 26 in the UK, and May 3 in the US.
Watch the newly released Super Bowl teaser below: