Which county?

If my stbx and I both live in Cabarrus county, can the divorce be filed in Mecklenburg county?

There is nothing in the law that bars you from filing in Mecklenburg county, but you risk having a judge throw it out because it is an out of county divorce simply because they want to. I would advise you to file in Cabarrus County. They have live divorces and things move very slow in Mecklenburg County.