I intend to marry a friend in Asia. I fully support them in every expense. They have no other source of income. Is this considered a dependent?

[Critter-3]

No ... that is called a spouse when you marry them  and a spouse can never be claimed as a dependent by the other spouse.   Instead you would file a joint return.  

[xmasbaby0]

And.....you cannot claim your GF/BF as a dependent at this time either----since you do not live together, among other reasons.     When you become married, post back for help with your 2023 return next year.  (Assuming you get married during 2023)   What you can enter then will depend on a few other things like whether your new spouse has a Social Security number, etc. etc. etc.