In this article I define and describe the current state of internationalization in psychology. Internationalization refers here to the approach in which existing or new psychological theories, methods, procedures, or data across cultures are synthesized so as to create a more culture-informed, inclusive, and globally applicable science and profession. This approach is essential to advance psychology beyond its Euro-American context of development and to achieve a more global applicability of its theories and professional procedures. Internationalization already has led to a better integration of cultural aspects in various psychological theories, to more insight into how to deal with methodological aspects of intact group comparisons (such as bias and equivalence), and to the development of guidelines in areas such as test development, test adaptations, ethics codes, and Internet testing. I review systemic and scientific climate factors in psychology that thwart the progress of internationalization, and conclude by suggesting methods of enhancing internationalization, which is essential for developing a truly universal psychology.