The third film in the franchise sees Tony Stark (Iron Man) coping with the events of Avengers Assemble and co-stars Gwyneth Paltrow, Sir Ben Kingsley, Rebecca Hall, Don Cheadle and Guy Pearce.
Its opening is the biggest of 2013, smashing the previous record held by Les Miserables and has exceeding the opening weekend of the previous two Iron Man movies which took £4,799,504 and £6,750,982 respectively.
International audiences have also taken to the film, helping it clock up an estimated $195.3 million in opening weekend sales, beating Avengers Assemble by more than $10m.
The UK box office results were the highest of the 42 territories the film has opened in to date. The film opens in the US and China later this week.