If my divorce was over 30 years ago, do I file single or divorced?

Divorced and single are the same thing except divorced asks about alamoney. 

There is no filing status of "Divorced".  If on December 31 you were married, you can file either joint or separate.  If you were not married, you file as single, or head of household (if you qualify).

Thank you very much 😊 

If you are divorced as of 12/31/2020 (let alone 30 years) you can file as Single provided you have not remarried.

Your filing status will be Single, but TurboTax does ask the question to select either Single or Divorced in the Personal Info section of the return.  In either case it will choose the filing status of Single.