Sport and diplomacy have been connected for decades in the realization of national interests in international relations whereby football has a special status around the world. As a team sport, football is worldwide popular due to its availability and national teams, which play it successfully, especially in the biggest international competitions, regularly attract a lot of attention. Croatia is a small country that has been active as a subject of international relations since the beginning of the 1990s whereby the world public initially perceived it through the war breakup of the former Yugoslavia, and very quickly as the homeland of world successful athletes. Croatia has gained special attention precisely at the World Football Cup in the 1998 and 2018, when its players played in the semi-finals and final. Based on the analysis of the relationship between sport and diplomacy in contemporary international relations, this study interprets the position of football in world sports and its influence on the reputation of individual countries whose national types achieve international success. At the same time, it evaluates the successes of Croatian football over the past three decades with an emphasis on the World Football Cups and presents the thesis that these successes made a key contribution to the positive perception and recognition of Croatia in international relations and in its image as a sports nation.