The article is devoted to the consideration of the best examples of ancient and ecclesiastical eloquence, which are the main sources of the formation of public rhetoric of Metropolitan Platon of Moscow. Representing science closely related to philosophical knowledge, public rhetoric is formed as an effective means of education, enlightenment, and influence on public opinion, so its priority task is inextricably linked with the search for and justification of truth which do not contradict moral principles. The special qualities of Church eloquence of FR. Platon, including persuasiveness, reasonableness, ethics, benevolence, are improved throughout his theological and teaching activities and allow him to become an outstanding rhetorician of the past and present. The analysis of the Metropolitan’s theoretical and practical heritage reveals the scale and international recognition of his personality and creativity. It is shown that modern Church and secular rhetoric require the involvement of both traditional and innovative forms and methods of communication with the audience. The use of the developed classical public rhetoric of Metropolitan Platon of Moscow enriches the methodology and method of speeches of both preachers and lay speakers. Thanks to psychological, ethical, and image factors, the idea of the speaker’s speech is conveyed to everyone.