There’s a number, mostly random B-list celebrities. Jenny McCarthy used to be the cashier at a local deli; we knew her right before she got her first Playboy spread. Rachel Nichols (nee Alexander) worked on the sports desk at my college newspaper and we’ve interacted a good number of times in the newsroom and on the field. Howard Levy (harmonic player for Bela Fleck and the Flecktones) was a regular at the cafe I worked at and we struck up a friendship (before I even knew who he was). We’ve had coffee together many times and exchanged emails. There’s a bunch of people well-known in the journalism industry, but they’re not household names. Oh, Buddy Guy – I’ve photographed a couple of events for his family. John Cameron Mitchell. There’s a whole bunch more, but I’m trying to think of people I have more than a fleeting moment with.
As far as famous relatives go, my great-grandparents on my paternal grandfather’s side were related somehow to either Mary or Jack Pickford (cousins, maybe?) I’m not sure exactly what the relation was, but my grandfather was named after Jack Pickford, and my name still has a “Pickford” in it as a result.
My dad also claimed that George “Spanky” McFarland of Our Gang fame was his first cousin once removed, but I’m not sure if that’s true or not.
Miss Indiana (1996 - Shani Nielsen) is a friend of mine.
I’ve met, in no order:
“Weird Al” Yankovic
Robert Goulet
Michael Stipe
Donnie Osmond
Jack Blades (from Night Ranger)
George Carlin
Lita Ford
Michael Damien
Pat Kilbane
And others I’ll remember after the edit window
After thirty years working on my family tree, I was convinced we somehow avoided any notability whatsoever. We had suggestions of links - Claptons from the village next to Eric Clapton’s ancestors but records petered out before any link could be found. Dodgsons from the village next to Charles Lutwidge Dodgson, likewise.
Then quite recently I stumbled upon Sir Alexander Fleming in a branch of the tree. Surprisingly closely related too - third cousin four times removed. So that’s pretty cool. Penicillin is a much better legacy than anti-vax sentiments, so take that Eric Clapton.
I rode an elevator with Bill Cosby (actor, comedian, rapist). I was introduced to Debbie Gibson (singer) on the beach. I also rented Gary Sheffield (professional baseball player) a wave runner. I once received an award from Christopher Hewett (actor: he played Mr. Belvedere in the eponymous sitcom). I asked Al Michaels (sportscaster) for the time.
[Moderating]
Since many famous people, including one of the two mentioned in the OP, aren’t noted as artists of any sort, this probably fits better in IMHO. Moving.
Related to? Not in a good way, nor closer than cuz-once-removed distance. I’ll be vague since both share my surname.
One of my great uncles killed someone famous. One of my cousins was a victim of a famous serial killer. Both events made national news.
Met? Just Hal Holbrook a long time ago. We were both watching the same play and stepped out at intermission for a smoke. He was surprisingly open and friendly.
No famous relations, though I married into a family that sold restaurant supplies. : ) My husband and I would joke that Dave Pirner was our stalker back in the day when we lived Downtown because we would run into him all the time. I’ve run into some famous people during my time working in a neighborhood cafe, such as Dan Wilson, Niki Taylor, Josh Hartnett, Mason Jennings and Brother Ali. I also worked with many actors and musicians of varying local notoriety. When I worked at the Midtown Global Market, Al Franken with his assistant. My coworker spilled coffee on Martin Dosh one Saturday. Marlon James was a regular and even Hilary Clinton came by one time, though I was off that day. MGM is an awesome spot to run into somebody famous because there’s a DMV in the basement. Everyone’s gotta get their license renewed or etc sometime.
I’ve met several celebs at weddings, one was my BIL’s, Peter Case was the entertainment . At Nick Schenk’s wedding (writer of Gran Torino) I got to chase down Mike Nelson from MST3K.
I grew up in California and my grade school had some workings with Bobby McFerrin so my class had done some assemblies with him before he was nationally famous. Little did I know he’d move to MN and I would see him around as his kids grew up. The one person I’ve NEVER encountered around here as a native: Prince.
While filming the VLA segment of CONTACT, Jodie Foster stayed at our house.
I went to grade school with Willie Stargell’s niece, which led to me meeting Mr Stargell. He was so cool, acting like he was the one fortunate to meet me. His voice was like Thunder.
At the same age I met Roberto Clemente just shortly before his death. He was at my friend’s house. My friend’s dad was Mr Clemente’s lawyer and was doing paperwork for his fateful trip to Nicaragua.
As an adult, I was with my kids when we met Dr Cyril Wecht. I told my kids Dr Wecht was a forensic pathologist. My daughter knew her brother didn’t know what that met, so she explained, “he cuts up dead people” which made my son’s eyes pop and jaw drop, which made Dr Wecht chuckle.
My mom was Burgess Meredith’s secretary in the 1940’s. 
Forgot to add: When the movie Wilson was filmed here, my husband’s shop building was used for some of the apartment scenes. I worked for a vegan cheese company at the time and the boss made some of the food featured in the movie. Woody’s got a neat party-bus. : )
For two years I had a part time job that included watering plants in the headquarters of Golden Bear International. Jack was in his office exactly once while I was there. No pleasantries were exchanged.
I attended elementary school with a future ex-wife of Bob Seger. She appeared in a few b-grade Hollywood movies. Annette ? (She changed her last name to something Hollywoody.)
When I was about six or seven years old I went swimming in the lake at Knoebels with (the) Hillary; Mom and Dad sat next to her parents on the beach and became Christmas card correspondents for several years.
Met many TV people through connections while working for The Dating Game and The Newlywed Game – so Chuck Barris, of course.
In Hollywood I had a stunningly gorgeous female roommate who called herself a ‘star fucker’. The list of big name celebrities she brought home was very long but they shall not be named since most of them were married. Through connections with her I became a regular at the Whisky a Go Go and had access to the upstairs dressing rooms, mingling with (and selling hash and weed to) whatever headliners were in town at the time.
Later moved to Malibu Colony. To drop a few names, Lee Marvin lived next door (became best buds with his son Chris), Larry Hagman was two houses down, John and Michelle Phillips were a few houses away (but they never socialized.) Robert Redford lived a little way down the beach but outside the actual Colony.
For a year or so I lived with a young actress whose mother only the youngest of you would not know of; she became well known on her own and still works as an actress. Her mother is over 90 and still living – many of you would consider her a household name.
My AA days. My home group was the Between Shows group, timed for a meeting between the 8 o’clock and midnight shows for showrooms workers; met several headliners who will also not be named.
I’m surprised at the number of people I could list that I feel I would rather mention by name. Ah, the good old days.
I’ve talked with Danny Marino, Jack Lambert and Mr. T. Drank with the last two.
Do you recall what Jack drank? Just curious. He’s a friend of mine and only has one beer at home. I’ll bring “good” beer over and he’ll try a sip, but that’s it.
Presuming that you are referring to the NFL quarterback, I had my picture taken with the same guy. I’ve also met pro golfer David Duvall, and my former boss once introduced me to NFL coach Mike Shanahan.
I almost forgot: Back when I was young and cute, I was chased around a gay bar in Columbus by a very drunk Paul Lynde, who had to be physically restrained.
Famous in Canada, maybe. W. O. Mitchell was my father’s second cousin. I didn’t know him but my mother introduced us at a meet and greet after he spoke at the local university. I talked about visiting my father’s farm probably before dad was born and having turnip fights with dad’s older brothers. “Yeah, that Orm, He was a real pain in the ass,” he said about my second oldest uncle.
I believe we were drinking beer, most likely Iron City because thats all I drank when I lived in Pittsburgh. His girlfriend/wife was downing shots called a blowjob when I met her before he showed up, was showung me that you down it without using your hands. Told me not to mess with her old man. I didnt need to be told.