Nevertheless, he woluldn't let the illness take over his life.
"I'm always being asked to go to Parkinson's things and spend time with Parkinson's people, having lunch or something like that," he told Sky News.
"And I don't approve of it. I don't think you should let Parkinson's define you and all your pals be Parkinson's people. I don't think it's particularly good for you. So I don't do it.
Regularly voted the best stand-up of all time in the UK, the former shipyard worker moved into comedy via a short stint as a folk musician. He's done a significant amount of straight acting for film and TV, including opposite Dame Judi Dench, as Queen Victoria, in Mrs Brown.
Married to Auckland-born comic actor and psychologist Pamela Stephenson, Connolly has done stand-up here often. Segments from his Too Old to Die Young tour were woved into Billy Connolly's World Tour of New Zealand, an eight part journey through Aotearoa.
Knighted in 2017, he appeared in Taranaki-shot The Last Samurai and as a giant dwarf warrior in Sir Peter Jackson's The Hobbit: The Battle of the Five Armies.
At the time, Jackson said: "We could not think of a more fitting actor to play Dain Ironfoot, the staunchest and toughest of dwarves, than Billy Connolly, the Big Yin himself. With Billy stepping into this role, the cast of The Hobbit is now complete. We can't wait to see him on the battlefield."
Fans were quick to comment on his standing down from stand-up.
This article was originally posted at NZ Herald and republished here with permission.