Samuel L. Jackson, Nicholas Cage, Seth Green, and Freddie Prinze Jr. are just a few actors who are comic book fanboys and collectors.
Jeff Goldblum and Clint Eastwood are jazz pianists who are supposed to be quite good, Peter Weller is a jazz trumpeter, and Anthony Stewart Head is a fantastic singer who released an album full of downtempo, “chill” music – sort of somewhere between new age and electronica.
It’s good to have a trade you can fall back on.
Wil Wheaton, Kurt Schilling and Vin Diesel are all…Gamers!
I’ve heard that Neil Young loves model trains, as well.
Julie Andrews keeps the heads of her enemies in glass jars in her bedroom.
Vin Diesel and the guys from System of a Down play D&D. Haha awesome!
Imagine that!
I might get dinged with a cite request here, but I’ve heard that Henry Kissinger would occassionally unwind at Disneyland . . . by putting on a uniform and selling popcorn.
One I can offer a cite for: he once appeared as a guest weatherman on CBS.
OK.
Cite?
According to Question 17 - yes.
The entire band X are Knitters. Not like Karen Allen and Julia Roberts, though. They started a second career as a folkie band.
Woody Allen plays jazz clarinet in a combo that has a weekly gig in a New York City club.
Gary Busey, after playing Buddy Holly in a movie, had a short run with a rock band.
Kevin Spacey, after playing Bobby Darin in a movie, recorded some jazz tracks, which may or may not see the light of day.
Rod Steiger, after playing a serial killer in No Way To Treat A Lady, took a job as No I’m Just Kidding About Rod Steiger! 
Former Steeler Lee Flowers knitted on the plane between NFL cities, as did most of my high school basketball team once we found out about that.
Rather fitting for a guy who wore a shirt that said “FLOWERS” every Sunday.
Alice Cooper collects watches.
Her Majesty Queen Elizabeth II apparently does really killer impressions. It’s said that when her bedroom was broken into by a deranged man a number of years ago, she helped herself recover from the shock by doing impressions of her cockney chamber maid going, “Bloody 'ell, mum, what’s ‘e doin’ in 'ere?”
Her grandfather George V’s enthusiasm for stamp collecting is well known.
Her Majesty Queen Margrethe II of Denmark does set designs for plays, and is also a textile artist and illustrator.
Adam Carolla pees in the sink.
Not really a hobby, just a fun fact.
“Red Ken” Livingstone, mayor of London, is well known in the U.K. for his lifelong interest in newts.
He is also an avid golfer.
Johnny Carson was an accomplished drummer.
There’s a comic, in the same vein/group as Buddy Hackett who collects third edition books (those being the ones when most of the errors have been purged from the text, apparently).
Gallagher is an inventor and apparently makes more money from that, than he ever did from his stand up routines.
LBJ liked picking dogs up by the ears. 
Except one. Chuck Norris still eludes her.
David Boreanaz collects and wears really, really wacky socks.Even when he’s wearing nice suits. I count it as a hobby, since he actively seeks these socks out. Here’s one example And another
I’ve heard several times that Mel Gibson and Jason Alexander both play Magic the Gathering. No clue about the source, though, and it seems kinda out of character for Mel to invite THE DEVIL’S WORK INTO HIS LIFE like that.
