Following the example set by The Avengers, the film will debut one week before it arrives in the US, according to ComicBook.com.
It is also rumoured to arrive in cinemas across Europe on the earlier date.
European fans are reporting that the new trailer dates the film's release at April 26, 2013.
Iron Man 3 will arrive in US cinemas on May 3.
The recently released trailer for the movie has apparently confirmed Ben Kingsley's Mandarin as the chief villain alongside a cast including Robert Downey Jr, Gwyneth Paltrow, Don Cheadle and Guy Pearce.
Watch the Iron Man 3 trailer below: