Are there any notable individuals who began life nonverbal but learned how to communicate orally and became successful?

I have heard many times that Albert Einstein didn't speak in his early years, so went to fact check it. Turns out it is not true, but I learned a fun fact that is hard to not share:

When he was two years old, his parents made him excited that he would get a little sister to play with. When she was born and he got to meet her, he was slightly confused and asked about the baby: "Where are its wheels?"

It’s always tragic to hear about a woman born without wheels :(
I don't get it. Why did he think a baby would have wheels??
- Apparently, when they said "to play with" he imagined some sort of of toy. :D

Are there any notable individuals who began life nonverbal ...

Literally everyone.

I think you mean something more like "... still nonverbal at the age of 5+ ... "

To that, I don't know of any. But I'd bet there are at least a few. The world is a big place, and betting against the existence of an extreme outlier is usually a bad bet.

I'm going to assume you clicked and replied without reading what community you're in?

This is an autism community.

Your comment essentially says "lol everyone starts out that way" then "other than that, idk", which is not helpful when the OP is asking for examples in regards to autism/ND individuals.
- You're absolutely right about being "not helpful when the OP is asking for examples in regards to autism/ND individuals."
  
  However it is helpful to point out when someone phrases their question poorly.
  Especially in a place known for people being quite literal minded.
  
  I’m going to assume you clicked and replied, without understanding what community you’re in?
  
  This is an Autism community.
  
  EDIT: To be clear, the previous two lines were a bit of a joke. Using most of your same words back to you, to make a very similar point that you may have missed, while you thought I may have missed something.
  
  At least I thought it was funny anyway.
- Answering this way was my first Impulse too since it is correct after all. Not taking things literally takes extra effort for me. And for some people it's close to impossible.
- Whoosh.

Temple grandin

I believe Oliver Sacks was non verbal as a child until 5 or 6 and hated music until his teens, where he took an interest in medicine and became a remarkable neuroscientist.

Helen Keller

Me. I talked using sing language in my early years.

When did you become verbal?
- I don't fully remember but around 4-6 years old.

That might be a hard list to create. While I understand the spirit of the message, I think it would be difficult to objectively define "non-verbal", then create a list of people that meet that criteria since they would have to publicly self-disclosed. I imagine we would mostly see this with autistic people that are advocates for the autistic community.