Is the mount for the lens of a T3i the same as the T3?

[David]

Yes, they are the same mount.

[Fmorales44]

Thanks for the help!

[Fmorales44]

Actually why I ask is that I want to buy the EF-S 18-200mm f/3.5-5.6 IS lens... Would it be a good fit for my T3 camera?

[jfo]

There's good discussion about that lens here:

http://forums.usa.canon.com/t5/Lenses/Resolution-problem-on-EF-S-18-200mm-f-3-5-5-6-IS-3/m-p/3931

"good fit" is entirely subjective depending on the subjects and conditions you want to shoot, your budget, etc.  Tell us a bit more and we'd be glad to be more specific.

[JohnfromPA]

Yes.  Any EF-S lens will fit any cropped sensor EOS camera, that includes the T3i, T3, 60D etc.  Any EF lens will fit the cropped sensor bodies.  However, an EF-S lens will not work on a full frame sensor body like the 5D series.  They require a lens labeled "EF".