Can a Canon FD 50mm lens fit on a 35mm Canon EOS camera?

No. The old Canon FD and the current EF are completely different lens mounts.
You could *make* your FD lens fit with an adapter, but these are more trouble than they're worth.
---
Hi John.
Yeah, I could have been more specific. Here goes:
None of (Canon's) digital SLRs have a split prism viewfinder to assist manual focusing; metering becomes a wee bit problematic; you lose infinity focus; any glass elements in the adapter will degrade your image quality; and for the privilege of using your old lens in this contorted manner you'll have to shell out roughly $50.
So there's that... or you could get a brand new Canon 50mm f/1.8 EF auto-focus lens for $90 retail or $70 used.
I'm happy for your own success with adapters but they are *not* for everyone.
http://photonotes.org/articles/eos-manua...

I am sorry to tell you that the first person who answered your question is completely wrong, there is an adaptor that allows you to use FD lenses on a Canon EOS camera.

However they can only be used in manual mode and they will be about 1.6 time longer than a 35 mm film camera would see.

I have an adaptor and I have used all of my FD lenses on my Canon digital SLR, I purchased my adaptors on eBay and they work well, there are adaptors made to fit the majority of digital SLR`s to take the old film camera lenses

like the other two said, you won't be able to. Unless you buy the adapter that allows it to mount on the body which degrades the image quality a bit.

i'd suggest you just get the cheap 50mm f/1.8. bad quality build but hey, it works doesn't it?