Pope Francis contribution to interreligious dialogue, especially through his encyclical letter Laudato Si, is the main theme of this dissertation. A presentation on the theme of interreligious dialogue in general was made, through reference works on this theme, in order to understand the challenges and importance of dialogue in times of religious pluralism and socio-ecological crisis. Thus, the ground was prepared to position Pope Francis contributions to the theme of interreligious dialogue, characterizing his action in favor of the dialogue of fraternity, in friendship and joint journey, which seeks the mutual enrichment and common good, working for peace, social justice, tolerance and religious freedom. The apostolic exhortation Evangelii Gaudium was first used as a basis, the programmatic content of his pontificate which foresees the practice of interreligious dialogue as part of the evangelizing mission of the Catholic Church. The understanding was reached that interreligious dialogue is within Francis s pastoral practice. The hypothesis question then arose: is there in Francis an original and singular contribution to the theme of current interreligious dialogue? Question answered positively. Through the analysis of Laudato Si, it was found an original contribution of Francis to the theme of interreligious dialogue, the construction of an integral ecology as a theme of interreligious reflection, encounter and collaboration. This research is part of the Laudato Si Research Project, coordinated by the research advisor teacher of this dissertation.