William Rowan Hamilton made great contributions to mathematics and physics, and in my opinion is one of the greatest scientists of all time, but I think he is surprisingly undervalued by the people of Dublin, which is where he was born.
Why there is not, for example, a statue of him in Henry Street, or a short biography of him at the airport? Instead, I have found just a few traces of his presence here (like the plaque under Broom Bridge, in a place so difficult to find that I missed it the first time).
Had Noble Prizes existed in his time, for sure he would have been awarded one.