This leaves it on target to be the most viewed film in Ireland this year, smashing the record held by Les Miserables.
Robert Downey Jr and Gwyneth Paltrow's movie took in more than twice the amount Les Mis did in its opening weekend.
Marvel's latest action-packed 3D adventure took in approximately €1m at the Irish box office over its opening weekend.
Oscar-winning musical Les Miserables was the most popular movie in the Irish box office up until April and had taken in a total of €2,323,507.
But Ironman is expected to far exceed this.
The film is currently sitting in 10th place on the top 10 list of movies in Ireland since January 2013, with a revenue of €1,061,796 to date. This increases to €1,603,864 with combined figures from the North.
American animated film Wreck-It Ralph is currently in second place in the Irish box office with a take-in of €2,047,687.047,
Despite being panned by critics, fantasy film Oz: The Great And The Powerful, is in sixth place so far with €1,404,281 to date.
Other popular films in the Irish box office in the last five months are Daniel Day-Lewis's Lincoln, in 7th place, Lord Of The Rings prequel Hobbit: An Unexpected Journey in 8th and Life Of Pi.