Denizenship means that a state grants certain economic, social, and (sometimes) partial political rights to long-term residents who are settled within its borders but do not possess its citizenship. The main objective of this article is to explore the phenomenon of denizenship in the countries of the European Union to see if there are important differences between the 15 countries of the “old” Europe and the 10 countries of the “new” Europe in terms of the expansion of denizenship. The main principles, development, and theoretical frameworks of denizenship will be presented, along with considerations on the presence or absence of international regulations that might influence policy-makers’ decisions on implementing denizenship within the European Union. As the research shows, denizenship is becoming common in both parts of the continent, blurring in this respect the East/West divide and becoming a sign of a “united Europe.”