Q. Can I file head of household for 2024 if the divorce is finalized before 12/31/24 and I am still living with my (now ex) wife & son?
A. Yes, since you are (will be) legally not married. There is an additional requirement that you have a "qualifying person". If you claim your son as a dependent, he will be your qualifying person.
The discussion about who is the custodial parent is probably not relevant, in your case, as you both lived with the child all year. Either parent (but not both) may claim the child as a dependent. If you can't agree on who will claim the child, then the rules are: first the parent the child lived with the most. That appears to be equal, so the 2nd rule is the parent with the highest income. For 2024, you do not need form 8332, since the child lived with you for all, or most, of the year.
