Tony Stark, the genius billionaire playboy philanthropist, AKA Iron Man, is one of the most intelligent characters in the Marvel Universe. He has a bachelor's degree in physics and engineering from MIT, two master's degrees (one in electrical engineering and one in business administration), and multiple doctorates. In the comics, he has been shown to have at least 14 PhDs.
However, it should be noted that the number of PhDs Tony Stark has varies greatly depending on which version of the character you're looking at. In some versions he only has a few, while in others he has dozens. The most important thing to remember is that no matter how many PhDs Tony Stark has, he is still an incredibly smart man who can hold his own against anyone else in the Marvel Universe when it comes to brains.