If the divorce is not finalized by the last day of the year then your filing status on a tax return would be Married, either Jointly or Separately.
Or if you have not lived with your spouse at any time during the last six months of the year, you have a qualified child as a dependent and meet the other requirements you could file as Head of Household. TurboTax support FAQ for Head of Household - https://ttlc.intuit.com/community/married/help/can-a-married-person-claim-head-of-household-filing-s...
