I don’t know.
I’ll advance Harry Connick JR as a nominee
Gonna leave the definition of “cool” pretty loose, but here is one more to show the vibe I was looking for…
James Hetfield
Absolutely does not have to be a rock star or celebrity.
Tell us why they are so cool
In the “I’m a Mac, I’m a PC” ads, the ad agency pretty well got their finger on the general perception of Cool.
I’ll vote for Barack Obama. Not only is he a highly evolved, educated, and compassionate human being, he also has flawless aplomb. Despite being under constant attack from racist troglodytes for his entire 8 years in office, he maintained his composure and dignity.
And he can sing
Seconded, Obama is most cool and he can dance as well as sing. My runner up would have to be Keanu Reeves.
Keith Richards. Read his autobiography “Life”, and you know why. He also plays a mean guitar 
.
Jack Black is, in my opinion, extremely cool.
Jack White is not cool at all.
Me. Sad isn’t it?
The Dalai Lama? The dude is never perturbed.
Keanu Reeves is pretty cool and Obama’s even cooler. I nominate Greta Thunberg. She is a climate change champion. She is no limousine liberal. In 2019, to attend the UN Climate Change conference without generating CO2 by flying, she sailed across the Atlantic. When they moved the next round of U.N talks from Chile to Madrid, she sailed back. She is relentless and persuasive. I hope she makes a difference.
Runner up in the “guys you’ve never heard of” category is Khaleel Sievwright. Raised in a low-in come family by immigrants, he learned how to play the piano, formed a band, and toured. Then he learned construction trades. Then he learned subsistence farming on a commune. He’s s self-taught painter. Currently, when he’s not organizing volunteers to build tiny houses (of his own design) for homeless people to survive the winter in Toronto, he might be reading philosophy, teaching chess, or advocating for those same homeless people.
I second Greta Thunberg. Also nominate Jane Goodall. And if she wasn’t disqualified by being dead, Ursula LeGuin.
I’d totally love to hang out some evening with Barack Obama, Tom Waits, and Quentin Tarantino. Beyond cool and into the realm of frosty.
I second Barack, but want to add Bill Murray to the list.
Billy Zoom
I’m tempted to go with Obama, too, but I’d have to qualify it by saying “coolest native English speaker” for me.
There may be non-English speakers who trounce him handily, but what makes them so damned cool isn’t accessible to me.
Unfrozen Caveman Lawyer was the coolest.
What, no love for Putin?
My first thought was also Keanu Reeves.