Can I use the Head of Household filing status if I'm claiming my fiance (girlfriend or boyfriend) or my fiance's child as a dependent?

Even if you are eligible to claim your fiance (girlfriend or boyfriend) as a dependent on your tax return, your fiance isn't a qualifying relative for the purposes of using the Head of Household filing status.

If your fiance's child is not related to you and you haven't adopted your fiance's child, the child is also not a qualifying relative for the purposes of using the Head of Household filing status, even if you are able to claim the child as a dependent.