I am an American living in the UAE, but I will graduate from a British school outside of the United States. Would I be considered an international student for American universities, and if not, how would I avoid out of state fees?
No, for admission/FA purpose you are still domestic students.
However you will be still charged OOS fee
So will it only be for a semester or for a whole year? I have family in the US so would it be possible to put their adresses in the application to avoid the OOS?
You won’t be eligible for in-state fees anywhere unless you, establish residency for another purpose besides attending college. Without your parents or guardians living in any state, you don’t get that benefit.
Remember, in-state tuition discounts by public universities are PAID by the taxes of that state’s residents. You’re not entitled any of your four years. Private colleges have no in-state discounts.
However, there are some colleges that will use this discount to entice particularly wanted students. You’d have to research this however.