Pope Leo XIV, newly elected as the 267th pope of the Catholic Church, delivered his first Mass at the Sistine Chapel on May 9, 2025, a day after his election.

The service marked a return to worship in a venue typically bustling with tourists but recently serving as a polling site for the conclave that selected him.

Leo, aged 69 and formerly known as Cardinal Robert Prevost, is notable for being the first pontiff from the United States.

In his homily, Leo initially spoke in English before transitioning to Italian.

He expressed gratitude to the cardinals for electing him to lead the Church, referring to the weight of the responsibility as a call to "carry the cross" of the Catholic Church.

He urged members of the priesthood to embrace humility, calling for them to make themselves "small" as part of their ministry, a sentiment reminiscent of the priorities of his predecessor, Pope Francis.

Leo’s election has been the subject of significant discussion, particularly regarding the implications of his American nationality amidst concerns about the nation's vast global political influence.

Cardinal Timothy Dolan of New York stated that Leo’s nationality did not play a significant role in the selection process, emphasizing that he is seen as the "father of the church universal." Similarly, Cardinal Wilton Daniel Gregory from Washington dismissed interpretations that linked Leo's election as a reaction to U.S. politics, affirming that the conclave aimed to strengthen the Christian faith rather than respond to political considerations.

During his first Mass, Leo highlighted the necessity of missionary efforts directed towards "corners of the world where it is desperately needed." His call for outreach aligns with established Catholic missions emphasizing service and support for marginalized communities.

Observers have noted potential parallels between Leo XIV and Pope Francis, including stylistic choices and a shared focus on inclusion and social issues.

However, there are indications that Leo may take a more traditional approach to certain theological questions, such as the ordination of women, which he addressed previously as a non-negotiable tradition.

As the papacy officially begins on May 18 with an inauguration Mass at St. Peter's Square, Pope Leo XIV's first general audience is scheduled for May 21.

Cardinal Arthur Roche remarked on the election, suggesting it reflects a continuity of purpose and unity left by Pope Francis, who had focused on pastoral experience within the Church's leadership.

Leo's leadership is positioned against a backdrop of extensive reforms in recent papacies, with an emphasis on maintaining essential doctrines while welcoming a diverse global congregation.