A:AnswerYes, it should fit it just fine. The T1i takes both EF and EF-S lenses. This lens falls under the category of EF-S, so it should fit any of the EOS Rebel cameras.
A:AnswerTechnically, yes it will work, but it's a heavy lens. We've put it on the SL1, and it makes it very awkward. It's best used on a larger, heavier camera. We use it on a Canon 60D.