Miguel Humberto Díaz (born September 29, 1963)[1] is an American theologian, diplomat and commentator who served as United States Ambassador to the Holy See.

As ambassador, Díaz helped launch the Religion in Foreign Policy Working Group of the Secretary of State's Strategic Dialogue with Civil Society.

The Working Group facilitates regular dialogue between the U.S. foreign policy establishment and religious leaders, scholars, and practitioners worldwide on strategies to build more effective partnerships on issues such as conflict prevention, humanitarian assistance and national security.

From 2001 to 2003, he taught and served as academic dean at St. Vincent de Paul Regional Seminary in Boynton Beach, Florida.

[11] Along with theologians such as Catherine LaCugna, Díaz argues that the life of God cannot be considered apart from history, but must be conceived as "for us, and for our salvation."

[12] Díaz gave his first speech on U.S. soil as ambassador on Friday, February 5, 2010, at St. John Vianney College Seminary in Miami, Fl.

[citation needed] After joining the University of Dayton, he was sought for analysis and comment[16] by the national news media, especially upon the resignation of Pope Benedict XVI in February 2013.