Did Deku Say “I Want to Be a Hero Too”?

No. Shoto Todoroki says it, during the U.A. Sports Festival, in the middle of his match against Izuku Midoriya. Deku is in the scene. He is the one being spoken to.

The verdict

Misattributed. Trusted quote coverage of the series gives the line to Todoroki and places it at the Sports Festival. None gives it to Izuku.

What is actually happening in the scene

Todoroki has spent the tournament refusing to use the fire half of his quirk, because it came from his father and using it feels like conceding something. Izuku, mid-fight, argues with him about it: the power is his, not his father's. The line is Todoroki breaking, and it is the moment he uses his left side for the first time in a real fight.

The reason it reads as a Deku line out of context is that it sounds like one. Wanting to be a hero despite not being built for it is the premise of Izuku's whole character. Handed to him, the sentence is a restatement. Handed to Todoroki, it is a reversal, and reversals are what make lines worth quoting.

Why this particular swap happens

Two reasons, and they compound. Izuku is the protagonist, so ambiguous My Hero Academia lines drift to him by default. And this line is delivered in a two-hander where both characters are arguing about heroism, so a quote card cropped to the sentence alone has a genuine fifty-fifty look to it.

It is worth being blunt about the wider hazard here. My Hero Academia attracts fabricated and reassigned quotes more than any other series this site covers. A verification pass over an early batch of eleven of its quotes confirmed none of them: two had no support anywhere and look invented, this one turned out to belong to a different character, and the rest described real scenes whose exact wording no source would reproduce.

How we checked

Dedicated Todoroki quote lists carry the line, one of them in body text rather than only as a heading, and both attach it to the Sports Festival match. A quote reproduced only inside a title-cased heading is evidence a line exists and poor evidence of its wording, so which of the two it is matters. See how this site sources quotes.