I have lens that does not fit my Nikon or Canon. Can someone tell me what camera this lens is for?
It is a Minolta mount! Have a Look at the rear cap of this lens. (If you still have) There you should see "For ..."
This is the Sigma SA mount. https://en.wikipedia.org/wiki/Sigma_SA-mount
which is like a cross between the pentax K mount (mechanically) and the canon mount (electronically)