Arguably, no one in the MCU is smarter than Tony Stark. He proved his intelligence time and time again, especially when he developed time travel and saved half of all life in the universe. He was a genius, but others still outsmarted him many times.
In general, Iron Man's biggest mistakes happened when he carelessly underestimated those around him. Whether it was a young boy he was mentoring or a global terrorist, Stark tended to let his ego get in the way of his interactions with other people. And if the other people were smart enough, they exploited those moments to get the upper hand on Stark's iron hands.
When Nick Fury Planted Black Widow Right Under Stark's NosePhoto: Iron Man 2 / Paramount Pictures
It's fair to say Tony Stark had a weakness for women. Nick Fury, a genius spymaster, used this weakness to his advantage by having one of his agents infiltrate Stark's inner circle by posing as an assistant. Fury knew that just by nature of getting the Black Widow, AKA Natasha Romanoff, in front of Stark, that he would ask her to be his assistant
The plan worked perfectly, and Stark, known for underestimating those around him, didn't suspect a thing.30232Was Iron Man outsmarted?
When Zemo Baited Iron Man Into Fighting Captain America And BuckyPhoto: Captain America: Civil War / Walt Disney Studios Motion Pictures
After Baron Helmut Zemo lost a lot of loved ones during the Avengers' time in Sokovia, he spent his life attempting to take down the so-called heroes. Zemo was something of a genius and knew that if he wanted to get rid of the Avengers, he would have to convince them to get rid of each other.
Zemo went after the Avengers' weakest link by framing the mysterious Winter Soldier for the death of King T'Chaka. The Winter Soldier, a former assassin, wasn't believable as the killer of a king, and Iron Man and Captain America were split on whether or not they should turn him in.
The feud eventually climaxed with Zemo showing Tony Stark that the Winter Soldier did, in fact, take the lives of Stark's parents. This reveal effectively ended the Avengers for a couple of years until Thanos went after Earth, which forced the group to reconvene. Zemo outsmarted Stark by using his own emotions against him.24445Was Iron Man outsmarted?
When Obadiah Stane Turned Off Stark's HeartPhoto: Iron Man / Paramount Pictures
Tony Stark ultimately outsmarted Obadiah Stane, but that victory didn't come without a few bumps on the road.
Stane took over Stark Industries as an interim CEO after Howard Stark's passing, before Tony was old enough to take over for his father. Stane decided he didn't want to give up control of the company, so he attempted to have Stark eliminated by an extremist group called the Ten Rings. His plot failed, and Stark recovered, returned, and built an arc reactor to keep his heart going. Stane decided that reactor would be great for earning some cash and upping the company's stock prices, so he used a short-term paralyzer to stun Stark and remove the arc reactor from his chest. This outsmarting was a bit of a long con because Stark had no reason to believe he couldn't trust Stane.19278Was Iron Man outsmarted?
When Ultron Disabled JARVIS And Took Loki's ScepterPhoto: Avengers: Age of Ultron / Walt Disney Studios Motion Pictures
Ultron, created by Bruce Banner and Tony Stark, was smarter than the sum of his creators. When Stark made Ultron, he attempted to play God, thinking an AI peacekeeping force would be best for humanity. But Stark was blinded by his own ego and created a monster he could not control.
Upon awakening, Ultron quickly brought down JARVIS, the less-sophisticated AI tasked with babysitting him. Ultron was also intelligent enough to grab Loki's scepter, a device key to his creation.12154Was Iron Man outsmarted?