In the past few years, the increasing role of public opinion in international arena from one hand, and also new developments in international arena from the other, has led to the development of a new approach in diplomacy which is called “Public Diplomacy”, and is employed as an instrument for pursuing national interests in the international arena by scholars, researchers, and executive individuals. Since there has not been noticeable study on the public diplomacy of the Islamic Republic of Iran, the authors attempt to assess Iran’s public diplomacy in a European country with selecting UK Muslims as their statistical population in this literature. Using a wide range of reports collected from some organizations and institutions which are active in the area of public diplomacy as well as Iran’s mission in England, besides interviewing 91 executive individuals and researchers of Iran’s public diplomacy, the literature addresses the following question: What has been the impact of Iran’s public diplomacy on UK Muslims? Using the main definitions of public diplomacy and also scrutinizing the activities of the missions and the representatives of the Islamic Republic of Iran in England, the article would accept or reject the hypothesis of Iran’s successful public diplomacy in England. At the end, some solutions would be proposed for a better implementation of an effective role of public diplomacy in strengthening ties with this European country.