The inclusion of celebrities in product or service promotion processes is a long-standing phenomenon that has over the years turned into a popular and effective trend that has not bypassed even the political communication. The aim of this paper is to investigate is this trend become a part of political communication, and, if so, whether celebrities are a significant factor in the political campaigns of parties and candidates, whether they can mobilize voters and what characteristics they must possess in order to move from a significant factor to a political communication weapon crucial for winning the elections. In order to fully explore and portray the integration of the "celebrity effect" into political processes in Croatia and the USA, the paper will, in addition to celebrities who have distinguished themselves as an important communication asset in political campaigns, present celebrities who become politicians or the public perceives as such due to the phenomenon of the personalization of politics. The paper covers political processes in Croatia and the USA with the aim of showing the effect of using celebrities in political campaigns as a long-standing trend in the United States and, on the other hand, its recent beginnings on the Croatian political scene.