Abstract The purpose of this paper is to introduce the thought of Brazilian statesman Rui Barbosa (1849–1923) on foreign policy and international relations from the vantage point of doctrinal reflection. In recent years, scholars have thoroughly sought to find the existence of a distinct Brazilian national thinking, building on the premise that there is no great diplomacy without a consistent foreign policy perspective. Thus, it would be mandatory to search for ideas and reflections that had assisted the foreign policy construction of the country, considered by many as well succeeded in most respects. In this context, the paper seeks to identify the possible foundations of Rui Barbosa’s vision on foreign policy and international relations, which is highlighted by a strong moral and religious foundation and settled on his contemporary conceptions on the pursuit of international peace.