This is the first movie in the Iron Man franchise not to be directed by Jon Favreau, possibly over creative differences with Marvel or because of his salary demands. He later said that not directing allowed him to have more fun with his character "Happy" Hogan, saying that he was like "a proud grandfather, who doesn't have to change the nappies, but gets to play with the baby."
The first Iron Man movie to gross over $1 billion, and the second Marvel movie to reach this mark, with The Avengers (2012) being the first.
The first cut was three hours and 15 minutes long. The final cut was two hours and 10 minutes long.
This movie was originally budgeted at $140 million, but after The Avengers (2012) became a huge hit, Marvel Studios and Disney upped it to $200 million, in order to allow Shane Black to make the best movie he could.
The first day Robert Downey Jr. and Sir Ben Kingsley met on-set, they snapped a photo together to send to director and mutual friend Sir Richard Attenborough.
Shane Black: [Christmas] Except for the prologue, the whole movie is set at Christmastime. Black's Lethal Weapon (1987), The Last Boy Scout (1991), The Long Kiss Goodnight (1996), and Kiss Kiss Bang Bang (2005) were also set at Christmastime. Last Action Hero (1993), which Black did not direct but helped write had at least a partial Christmas setting.