Can sigma 24-70 for Nikon fit to a canon camera?

I have a sigma 24-70 not the art version the older one. Is there an adaptor or something that can make the lens fit to canon eos 5d mark 3. If so will the lens work properly?

Yes

Yes, via an adaptor, but… You risk poor optical performance and you almost certainly will not get all the functions which you would have with a lens designed for that Canon.

Basically, sell the lens for Nikon, and buy it for Canon.

With an adapter, yes, but without autofocus or aperture control, it just isn't worth the trouble.

No.

The mounts are completely different. There are adaptors that allow the use of Nikon lenses on Canon bodies but you will have to use the lens manually for both focus and aperture controls. If the lens has no aperture ring, there will be no aperture control. Aperture will be always set to minimum. It won't be worth the effort.

Not a worthwhile pursuit.

Yes, there are a few companies that manufacture such adapters BUT not a worthwhile pursuit since you will pay money for an adapter that will cause you to lose Autofocus and Aperture automation use in Auto mode; you might as well sell it and get the same focal length lens for the Canon (save money by buying used at a reputable photo shop like B&H Photo (NYC) or KEH.com, on the Internet). It simply ain't worth the hassle.