If people who live in Germany are Germans then people who live in Spain are called what?
A person who lives in Spain is called a Spaniard, or Spanish.
Not technically as Spain was officially nonbelligerent, which means the don't participate in conflict. In fact, Spain did assist both the allies and Germany. there were some volunteers from some of the people of Spain for both the allies and axis. However, the allies putted economic pressure onto Spain and military demands from Germany. So Spain was neutral during WW2 but did assist both sides.