Anyone know if a Glock 20 (10mm) slide will fit on a Glock 17 (9mm) frame?

It does not. The slide on the 20 is wider and longer than that of the 17.

it also wouldn;'t feed right, or BE safe to do so??

Ok. I know some do interchange just wasn't sure about this one.

Thanks guys

only models that interchange are MADE to do so, its not like its a just a GLOCK is a Glock here, if you go on the Glock site it will (It used to) have info there on what can be done and not too
going from a 9 mm to a 10 mm , is a jump in power and you need a frame built to handle it

That's what I figured. I was wondering because I'm helping a guy who's father in law passed away and has TONS of guns, parts, ammo etc...and one of the boxes had multiple Glock slides and I always wanted a 10mm so I got excited for a minute lol

I have several 10 mm's including Glocks, its a great caliber
BUT if this person has slides, he should have had the frames too, never seen them sell just slides for 10 mm
and I was a Glock Gold stocking dealer for 10+ yrs, THAT or you could TRY and find a used Glock 10 mm and then have a spare slide and be ahead of the game
OR try again contacting Glock and ask then if they would sell you JUST a frame, as that is the registered part of it??

I blew up a Glock 17(first gen)once, and sent it back to Glock, and they gave me a NEW frame a 3 rd gen frame, and same old Serial number, to correct things for me.
they had awesome customer service when I dealt with them, but that was 15+ yrs ago, customer service has changed a lot in many company's since then, but I would TRY< never hurts to ask!
and might be surprised what they Might do for you, as never know, maybe there still a top shelf service company??

He may have a pistol, over 150 pistols and we haven't gone thru them yet. But he did the gun show stuff so it looks like he has a lot of random stuff that he was buying/selling.