My brother and I both have wide set eyes (eyes that are further than one eye width apart) and so does our dad. I've looked at celebrities who also have wide set eyes and it seems that more often than not, their children's eyes are also wide set. Some examples are Jaqueline Kennedy Onassis, Kate Moss, and Chance the Rapper. So my question is: are wide set eyes hereditary and/or are they a dominant gene?

I don't know of evidence that there is a single gene or set of genes responsible for having 'wide eyes'. So whether 'wide eyes'  are dominant, I don't know and don't think we know, but wide eyes are probably at least partially going to be hereditary, like most body features I think.