do i need a passport to travel to any us territory ?

Need more info.
-Where are you from?
-Your nationality?
-Where are you planning on going?

depends on if you're travelling entirely within the us boundries and not planning any stop overs/flight changes

If you are traveling there from within the US, then you do not need a passport. (Of course, you still need picture ID to clear security. That can be a passport, but it doesn't have to be if you have another form of acceptable ID such as a drivers license.) It's a domestic flight, just as if you were flying to Florida or Arizona. Contrary to what a previous answer says, it doesn't matter if you have a stopover or a connection as long as it is also in the US.

If you are traveling from outside of the US, then you need the same documentation that you would need to fly to anywhere else in the US.