This paper describes dynamic aspects of the vocative systems in Russian, British, and American political communication. It analyses birthday greetings addressed to the General Secretaries of the CPSU Central Committee, Leonid Brezhnev and Mikhail Gorbachev, the Presidents of the Russian Federation, D.A. Medvedev and V.V. Putin, the Queen of Great Britain Elizabeth II, and the Presidents of the USA: J. Carter, J.G.W. Bush, B. Clinton, J.W. Bush, B. Obama, D. Trump, and D. Biden. The analysis of typological similarities and differences of Russian, American, and British political communication is presented on the material of vocatives used in the considered greetings; linguocultural peculiarities of political discourse of Russia, the USA, and Great Britain are characterized. In the speech genre of congratulations, status vocatives are of crucial importance in American and British political discourse; meanwhile, in Russian political discourse, anthroponyms prevail. Russian and American discourse is characterized by a greater variety of vocatives (anthroponyms, special status and general status vocatives, zero and emotive ones) compared to British discourse (special status and general status vocatives, zero ones). The identified functions of vocatives (appellative, emotive, social-regulative and etiquette) in the considered congratulations are aimed at reducing the social-status distance between the addresser and the leader of the country and at creating a positive emotional state of the addressee. Additional vocative means can include the adjectives dear, dearest, best, favorite and the pronouns my, our. The article discusses the national-cultural features of vocatives in accordance with the interpretation of the communicative category of politeness in Russian and English linguistic cultures and the specificity of speech etiquette.