Can I have a roommate move into my home prior to the finalization of my divorce?

If the home is in both your names, you has an equal say on what is done with it--including whether there are any tenants (which is what  a roommate is). So the answer is that yes, he can probably stop you from doing this. You need to either negotiate with him to get his agreement to do this (which may mean giving him a share of any rent, to which he'd be entitled) or you need to make the disposition of the home part of the divorce and get that finalized. What you can't do is change the status quo or infringe on his ownership rights unilaterally; there needs to be, again, either a simple agreement between the two of you alowing this or the home needs to be taken care of in the divorce.

In what stage are you in the "finalization" process?  Have you entered in to any type of separation agreement or settlement agreement with your soon to be ex?  What does it say?  Have you been awarded exclusive use of the house at this point in time?  Have you agreed to an award of the house as your asset?  All this matters here in giving any form of guidance to your question.  It may be best for you to ask your divorce attorney on the matter.  He or she will best be able to advise you in light of the agreements made thus far.  Be prepared for the fact that you may have to wait if he will not agree.  Good luck to you.