"Would a 27 1/2 one fit?"

Yes. Easily.

It may if that is the outer dimension. The clips that hold them in place are usually another 1" or so, which means it's pretty close. They may have to notch the inside of your cabinet.

If 27" is the inside bowl width, I do not think it will fit. (assuming this is an undermount sink)

I have used the Allora 27" undermount sink a few times and my clients LOVE the sink! 27" sinks were hard to come by for years, but some of the manufacturers are smartening up to it!!! Thank goodness!!!! Here it is: ALLORA 27" UNDERMOUNT - CLICK HERE

Thanks Barnes, I thought it may be a close fit? The Allora 27 is exactly what I'm looking for in my condo. Thanks so much! I may order it now just to make sure it fits with my cabinet. I also found a similar one on Amazon.

The Blanco BL441024 Stellar Super Single 28" fit my 30" cabinet very nicely. It is 9" deep.

Barnes:

Please click on the links before you post. That sink will fit easily. No clips.