One of the most anticipated films in the upcoming Marvel Cinematic Universe roster is, undoubtedly, Avengers: Infinity War. Bringing together damn near every Marvel superhero we've seen onscreen over the last decade or so, this film is going to be like one epic high school reunion. However, there's reason to believe that some major MCU storylines will be ending, as might be the case if Iron Man dies in Avengers: Infinity War. The chances are high that one of the first Marvel superheroes we met during the MCU's Phase One — think Iron Man, Captain America, and Thor — will not survive Infinity War, and there's a really good chance it really could be Iron Man.
It's been hinted at by Marvel head Kevin Feige that a very popular MCU character will most likely die in Infinity War. While he didn't name names, he did say this: "'We have another two years of hard work to even finish these movies,” Feige said, according to Comic Book. “And they [the actors] have a lot of hard work to do, so that's all we're thinking about, is completing those and delivering on the promise of those. Where it goes beyond that, we'll see.'"
It stands to reason that many of the actors who have been around since Phase One will be coming to the end of their contractual obligations with these films, so it would be fitting to neatly write them out of the MCU without leaving the door open for their return. In this way, it makes sense that Iron Man is topping the list of superheroes most likely to die in Infinity War.
Additionally, considering the plot and the extent of the involvement of each of the characters is being kept under wraps is lengthy, we can only look to IMDb and previous MCU films to get a good sense of Iron Man's fate. Firstly, the simple fact is that Robert Downey Jr.'s (who plays Iron Man) future film roles don't include any more Marvel films. After Infinity War, he's set to play iconic characters Dr. Dolittle and Sherlock Holmes and will most likely star in a biopic about Dr. John Brinkley. This noticeable lack of Iron Man reprisals give credence to the idea that Iron Man dies in Infinity War.
Finally, let's take a moment to consider Iron Man's past actions when fighting on a team. In the first Avengers, the climax of the film rests on Iron Man's ability to think unselfishly and fight for the group rather than personal glory. In doing so, he flies into outer space to vanquish the aliens threatening New York and comes close to death in the process. It stands to reason that Iron Man might do something just as heroic for the rest of the team once again (and with more superheroes involved, the stakes are higher) when their backs are against the wall in the fight against Thanos.
All in all, without any concrete evidence that Iron Man is in fact the one person who will perish in Infinity War, it's tough to say if it's true or not. That said, the odds are very high, so you may want to start saying your good-byes now.