In Poland, the region where ethnic diversity is the most noticeable is the Opole region, characterized by a high concentration of ethnic Germans. Because of their origin, they have German citizenship, or the right to acquire it, in addition to Polish citizenship. The political changes of 1989 have enabled this particular population group to undertake a number of initiatives and activities, mainly focused on German minority organizations. Moreover, until Poland's accession to the EU, the increasing wage migration of the ethnic German population became a key factor in the development of their region of origin, the Opole Province. In addition to the cultural diversity, the Opole Province is characterized by a number of other important features, including intensive wage migration to the West, relatively low unemployment, a higher than average standard of living, a well-developed economic and social infrastructure, and a high degree of urbanization and industrialization. It appears that these characteristics are related both to the people of German origin living in the Opole region and to the activity of the German minority organizations, that have had a significant impact on the socio-economic diversity of the area and on the development of the whole Opole region as well. The aim of the paper is to show the role of ethnic diversity in the context of regional development, as well as the fact that ethnic diversity can be a significant regional potential, using the example of the German minority in Poland. The conducted studies show that the role of ethnic diversity, understood as the German minority, is considered positive and that its existence and activity should be classified, on the one hand, as an essential contribution and added value from the regional perspective and, on the other hand, as a great potential for the further development of the Opole Province.