Many scholars study polymathy. I'm pretty interested in it myself. However, I find actual polymaths at least as interesting. I'm fascinated by their breadth and depth of knowledge.
Years ago I wrote a lot about polymathy and a little bit about actual polymaths.
In restarting this project, I intend to write about people whom I consider to be actual polymaths. Maybe they are, maybe they aren't. But they are certainly fun to think about.
And as I wrote a long time ago, lists of polymaths are fun. There are lots of them out there. Again, maybe you agree that everyone on those lists is a polymath, maybe you don't agree. But the key thing is to get the names and then start reading about them because they have some really incredible accomplishments.
I have found you some lists to get you started. You can see them here, here, and here.
You may remember that the famous historian Peter Burke recently wrote a book about polymaths. I was going to review it here a couple of years ago, but I ended up not doing it because it turns out that I'm not much of a book reviewer. I'd rather read someone else's review of a book than provide my own. Burke discussed 500 (!) polymaths, but, unfortunately, I can't find a list of his polymaths on the internet. So you'll have to buy his book and discover them for yourself.