I vaguely remember similar threads from back in the day. Those are probably filled with people we are forgetting about.
Claude Shannon, the father of information theory, was well known for unicycling around. Claude Shannon - Wikipedia
Wikipedia has a list of people from other fields: Unicycle - Wikipedia
I don’t know who is most surprising, maybe Donald Rumsfeld
Chris from Mrbeast
Has somebody already mentioned Erlend Loe? (He is also on this forum)
Pity he makes his living on 2 wheels not 1 though
I think his potential earnings on one wheel would be fairly slim 
Sad to know that he’d have a lower balance if he rode a unicycle for a living…
Not quite on topic, but here are Rob Warner (semi famous MTB racer/commentator) and Charlie Hatton (up-and-coming British DH mountainbike racer) attempting to ride a unicycle:
https://www.instagram.com/tv/CfZeb1sK8_Y/?utm_source=ig_web_copy_link
Now that is a bit of a coincidence – I was just watching “Rob Meets…” on Red Bull TV a couple of nights ago (as you do…) and saw him attempting to ride a unicycle while with Finn Iles – see the link at 11:35. Finn does manage to hop up some steps though starting at about 5:45…
Jamie Lissow, the standup comedian happened to live in my town some years back. He was a co-host on a local morning radio show at the time. Since then he has been an actor on Real Rob and was the producer of the show Man With a Plan on CBS.
In 2011 I was riding muni on some local trails and I passed him and his family at the the top of a hill climb. He asked me about the sport and showed interest in learning. We talked, though he never mentioned his profession and I didn’t know who he was, but he must have given me his name or email before we parted ways. At home I googled him, learned he was on the locally famous The Wease Show and figured he might bring up our encounter on the show, so I recorded the next one. And he totally talked about me and turned it into a little phone call-in game! It made me feel famous for a while. 
Over the next months he learned to ride, bought a 26" Nimbus and we rode some light muni together. All credit to Jamie for getting inspired, deciding to learn, and doing it, but I’ll always be a little tickled that I was at least part of his inspiration. He has long since moved away to work on his career.
Talking about me on the show:
Talking about learning:
Also when he moved away he gave me his pair of running snowshoes. It’s silly but I also feel tickled when I use my famous pair of snowshoes. lol
Dr. Claude Shannon was also one of the founding members of the Unicycling Society of America. I’m currently reading a book about him.
Absolutely! 
More mountainbikers, this time Eddie Masters, a professional enduro racer.
I just found the video here:
He even rides a unicycle on a slackline 
Gates McFadden, best known as Beverly Crusher on Star Trek: The Next Generation. She’s also a dancer and choreographer. 
Bejo, a Spanish raper has this video where he rides a unicycle while dress up as an alien.
