What's a word for somebody you’ve never met?

Solution 1:

There is also role model: a person looked to by others as an example to be imitated.

Solution 2:

While he is a stranger, he is also a mentor.

Solution 3:

I would use either role model or mentor.

Solution 4:

Could you just go for the emotional component, and say that that man is an inspiration?

For my ears it's a broader word that better grabs the 'influence in some way' aspect of it all esp if you pair it with the "I've not met him" opening. For example:

I'm trying to think of a word for somebody I've never met, but who has influenced me.

Like Steve Jobs, I've never met him, but he continues to teach me.

He's like an invisible hand to me. An unmet teacher. An inspiration!

(gratuitous exclamation mark added for effect)